• Structural Engineering and Mechanics
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• v.90 no.6
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• pp.591-600
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• 2024

This study investigated the acceleration response and shape change characteristics of a gravity quay wall according to the magnitude of the applied acceleration. The quay wall was defined as a port facility damaged by the Kobe earthquake. Four experimental scenarios were established based on the inclination condition grades, considered to be a significant defect factor in the quay wall. Then, the shaking table test was conducted using scaled-down quay wall models constructed per each scenario. The ground acceleration was gradually increased from the peak ground acceleration (PGA) of 0.1 g to 0.7 g. After each ground acceleration test, acceleration installed on the wall and backfill ground and inclination on the top of the wall were measured to assess the amplification of peak response acceleration and maximum response amplitude and the change in the inclination of the quay wall. This study also analyzed the separation of the quay wall from the backfill and the crack pattern of the backfill ground according to PGA values and inclination condition grades. The result of this study shows that response acceleration could provide a reasonable prediction for the changes in the inclination of the quay wall and the crack generation and propagation on the backfill from a current inclination condition grade.

• Journal of the Korean Wood Science and Technology
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• v.45 no.5
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• pp.640-649
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• 2017

A comparative research on the traditional standard wood walls and other light-frame wood walls is necessary to expand the base of wooden buildings and improve consumer satisfaction. Therefore, in this research we looked for new possibilities through comparison of performance between standard wood wall and newly presented staggered stud wood wall. First, the strength characteristics of staggered stud wood walls were evaluated and the those of standard wood walls were compared. The ultimate load of the standard wall was larger than that of the staggered stud wood wall, because the cross section of the wood making up the standard wood wall was larger than that of the staggered stud wood wall. However, the statistical analysis between the two groups didn't showed a significance of 95% confidence level. This means that, staggered stud wood walls have shown the possibility of replacing the standard wood wall. Because the cross-section of the stud in the staggered stud wood walls is smaller than that of the standard wall, the material can be saved. Therefore, staggerd wood stud wall is judged to be more economical than the standard wall. In addition, since the area of the insulation also increases, improvement of the heat bridge is also expected.

• Journal of the Korean Solar Energy Society
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• v.23 no.1
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• pp.1-8
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• 2003

Various efforts to combine new high-tech materials with solar system have been progressed nowadays in order to improve the performance of the existing passive solar system. TIM(Transparent Insulation Material) replacing the conventional outer building envelope glazing as well as the wall is good example for this trend. TI integrated wall is a thermal mass wall with a special shaped TIM instead of using typical envelope materials The tested TIM type is a small(diameter 4mm and thickness 50mm) capillary tube of Okalux model and cement brick(density 1500kg/m3). The purpose of this study was to analyze the thermal performance through the actual measurements performed in a test cell. This study was carried out to justify the following issues. 1) the impact of Tl-wall over the temperature variations 2) the impact of mass wall surface absorptance over the transient thermal behavior and 3) the impact of thermal mass wall thickness over the temperature variations. Finally, as results indicated that the peak time of room temperature was shifted about one hour early when absorptance of thermal mass wall changed from 60% to 95% for the 190mm thickness thermal mass wall test case. the temperature difference of both surfaces of thermal mass wall surface showed about $23^{\circ}C$ during a day of March for the 380mm thickness thermal mass wall case. However, the thermal mass wall was over-heated by outside temperature and solar radiation in a day of May the temperature difference of both surfaces of thermal mass wall surface was indicated $10^{\circ}C$ and inside temperature was observed more than average 22C.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.5
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• pp.18-25
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• 2016

This research purposed to study a structural effect on curtailment of upper shear wall in frame-shear wall structures, using MIDAS-Gen. In this study, the analysis variables were the story number of curtailment of upper shear wall, change of column section in every 2 stories and change of shear wall thickness in every 2 stories. In order to analyse a structural effect on curtailment of upper shear wall in frame-shear wall structures, we studied the distribution of shear force and overturning moment according to curtailment of shear wall, the inflection point of shear wall from shear force/overturning moment and the lateral stiffness. The results of study proposed the quantitative influence that the curtailment of upper shear wall in frame-shear wall structures had on the structural performance such as lateral stiffness. Furthermore, it is verified that the results of study can be very helpful in catching the materials on the structure design for a reasonable frame-shear wall system.

• Journal of the Korean Geosynthetics Society
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• v.16 no.4
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• pp.43-55
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• 2017

The purpose of this study is to investigate the effect of traffic loads on retaining wall stability. There is insufficient research on lateral earth pressure on retaining wall due to traffic load. In addition, limited detailed designs of retaining wall for transportation including number of lanes of road, magnitudes of axle loads, and vehicle formations are available. Because the lateral earth pressure on the retaining wall due to traffic loads is a function of the lateral distance from retaining wall, the wall height, and the locations of lanes, the analysis of lateral load on retaining wall from traffic loads is performed with direct or indirect reflection of these factors. As a result of the analysis, lateral earth loads induced from traffics can be considered negligible if the lateral distance of traffic load from wall exceeds the height of retaining wall. Therefore, it is practically reasonable to consider traffic loads within a lateral distance between wall and traffic load of the height of retaining wall.

• Physical Therapy Korea
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• v.24 no.1
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• pp.79-85
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• 2017

Background: The wall squat is considered an effective exercise because it can reduce the knee load and prevent excessive lumbar movement. However, the relationship between wall squat performance and strength of knee extensors and hip extensors remained unclear. Objects: The purpose of this study was to compare the strengths of the knee extensors and hip extensors between groups with low and high wall squat performance. Method: Nineteen males (low performance group: 9 subjects, high performance group: 10 subjects) participated in this study and performed wall squats. The subjects who were performing less than 30% of the average wall squat count were classified into the low wall squat performance group (less than or equal to 4 times) and the subjects who performed more than 30% of the average wall squat count were classified into the high wall squat performance group (greater than or equal to 8 times). Knee extensor and hip extensor strength were measured with a strength measurement system. An independent t-test was used to compare the strengths of the knee extensors and hip extensors between the groups with low and high wall squat performance. Results: The ratios of knee extensor and hip extensor strength to bodyweight were greater in the high wall squat performance group than in the low wall squat performance group (knee extensors: p<.001; hip extensors: p=.03). In the high- and low-performance groups, the ratios of knee extensor strength to bodyweight were $42.74{\pm}5.72$ and $30.76{\pm}8.54$, respectively, and the ratios of hip extensor strength to bodyweight were $31.95{\pm}10.61$ and $20.66{\pm}11.25$, respectively. Conclusion: Our findings suggest that knee extensor and hip extensor strength are needed for high wall squat performance. Thus, exercise to increase the knee and hip extensors strength can be recommended to improve squat performance.

• Journal of architectural history
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• v.19 no.6
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• pp.121-135
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• 2010

This study was to analyze the architectural characteristics and facade construction of brick masonry auditorium through the Auditorium of Namsan Primary School in 1936. The results of this study were described separately as follows. 1. The auditorium is located away from the school buildings, and its plane is a chamber of rectangle type with an entrance installed on each of the four sides. 2. The external appearance is Renaissance eclectic style, laid red bricks on the lower wall of the window and having a mansard roof. The front and the rear are symmetric with respect to the projected wall at the center. 3. As to the structure of the building, a concrete lower wall was built on the concrete continuous footing, and the brick wall was constructed on the lower wall. The roof is queen post roof truss, and the wall girders were installed on the brick wall. 4. The auditorium has had a number of repairing and maintenance works, which changed the roof and windows outside and the floor, walls, ceiling, etc. inside. 5. The decorative elements of external appearance include lower wall, brick wall, entrances, windows, roof, and dormer windows. The brick wall gives verticality and solidity to the surface of the wall, and the lower wall and wall girders are connected like a cornice of the wall. The surface of the mansard roof and dormer windows express a stable vertically oriented shape.

• Journal of Korean Association for Spatial Structures
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• v.13 no.2
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• pp.83-91
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• 2013

The core aim of this dissertation is to empirically scrutinize a strength characteristic of beam-column frame subjected to the cyclic lateral load, a beam-column frame of un-reinforced masonry wall, and a shear wall frame. First and foremost, I embark upon making three prototypes vis-$\grave{a}$-vis this research. By conducting this process, I touch on an analysis of cyclic behavior and a damage characteristic of the beam-column frame, the beam-column frame of un-reinforced masonry wall, and the shear wall frame. What is more, through the previous procedure, the next part delves into the exact stress transfer path and the destructive mechanism to examine how much and how strong the beam-column frame of un-reinforced Masonry Wall does have a resistance capacity against earthquake in all the architecture constructed by the above-mentioned frame, as well as school buildings. In addition to the three prototypes, two more experimental models, a beam-column frame and shear wall frame, are used to compare with the beam-column frame of un-reinforced masonry wall. Lastly, the dissertation will suggest some solutions to improve the resistance capacity against earthquake regarding all constructions built with non bearing wall following having examining precisely all the analysis with regard to not only behavior properties and the damage mechanism of the beam-column frame and the beam-column frame of un-reinforced Masonry Wall but also the resistance capacity against earthquake of non bearing wall and school buildings.

• Advances in concrete construction
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• v.11 no.1
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• pp.33-43
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• 2021

A new type of composite insulated concrete sandwich wall (ICS-wall), which is composed of a triangle truss steel wire network, an insulating layer, and internal and external concrete layers, is proposed. To study the mechanical properties of this new ICS-wall, tensile, compression, and shearing tests were performed on 22 specimens and tensile strength and corrosion resistance tests on 6 triangle truss joints. The variables in these tests mainly include the insulating plate material, the thickness of the insulating plate, the vertical distance of the triangle truss framework, the triangle truss layout, and the connecting mode between the triangle truss and wall and the material of the triangle truss. Moreover, the failure mode, mechanical properties, and bearing capacity of the wall under tensile, shearing, and compression conditions were analyzed. Research results demonstrate that the concrete and insulating layer of the ICS-wall are pulling out, which is the main failure mode under tensile conditions. The ICS-wall, which uses a graphite polystyrene plate as the insulating layer, shows better tensile properties than the wall with an ordinary polystyrene plate. The tensile strength and bearing capacity of the wall can be improved effectively by strengthening the triangle truss connection and shortening the vertical distances of the triangle truss. The compression capacity of the wall is mainly determined by the compression capacity of concrete, and the bonding strength between the wall and the insulating plate is the main influencing factor of the shearing capacity of the wall. According to the tensile strength and corrosion resistance tests of Austenitic stainless steel, the bearing capacity of the triangle truss does not decrease after corrosion, indicating good corrosion resistance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.9
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• pp.3194-3210
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• 2022

Wall obstruction is the main factor leading to the non-line of sight (NLoS) error of indoor localization based on received signal strength indicator (RSSI). Modeling and correcting the path loss of the signals through the wall will improve the accuracy of RSSI localization. Based on electromagnetic wave propagation theory, the reflection and transmission process of wireless signals propagation through the wall is analyzed. The path loss of signals through wall is deduced based on power loss and RSSI definition, and the theoretical model of path loss of signals through wall is proposed. In view of electromagnetic characteristic parameters of the theoretical model usually cannot be accurately obtained, the statistical model of NLoS error caused by the signals through the wall is presented based on the log-distance path loss model to solve the parameters. Combining the statistical model and theoretical model, a hybrid model of path loss of signals through wall is proposed. Based on the empirical values of electromagnetic characteristic parameters of the concrete wall, the effect of each electromagnetic characteristic parameters on path loss is analyzed, and the theoretical model of regional path loss of signals through the wall is established. The statistical model and hybrid model of regional path loss of signals through wall are established by RSSI observation experiments, respectively. The hybrid model can solve the problem of path loss when the material of wall is unknown. The results show that the hybrid model can better express the actual trend of the regional path loss and maintain the pass loss continuity of adjacent areas. The validity of the hybrid model is verified by inverse computation of the RSSI of the extended region, and the calculated RSSI is basically consistent with the measured RSSI. The hybrid model can be used to forecast regional path loss of signals through the wall.