• Journal of the Korean GEO-environmental Society
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• v.18 no.9
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• pp.11-18
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• 2017

Numerical analysis method for prediction of pile behaviour characteristics has widely been used in detail design process before construction because field static loading test requires high cost. However, the reliability verification of numerical analysis of result is not permitted compare with field test. In this study, to verify the numerical analysis results, pile behaviour prediction was compared with field static loading test results. For exact analysis of interaction between pile and ground, soil investigation and in-situ test such as boring, SPT and bore-hole shear test were performed before pile static loading test. During the static loading test, pile behaviour characteristics were analyzed under every loading condition. After static pile loading test, numerical analysis was carried out under same condition with static pile loading test. In the numerical analysis, to apply same loading condition with each loading condition in the field test and to compare with between the results of numerical analysis, the field test results for reliability were verified with the results of numerical analysis.

• Smart Structures and Systems
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• v.2 no.2
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• pp.115-126
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• 2006

The Terra-Scope system is an affordable 4-D down-hole seismic monitoring system based on independent, microprocessor-controlled sensor Pods. The Pods are nominally 50 mm in diameter, and about 120 mm long. They are expected to cost approximately $6000 each. An internal 16-bit, extremely low power MCU controls all aspects of instrumentation, eight programmable gain amplifiers, and local signal storage. Each Pod measures 3-D acceleration, tilt, azimuth, temperature, and other parametric variables such as pore water pressure and pH. Each Pod communicates over a standard digital bus (RS-485) through a completely web-based GUI interface, and has a power consumption of less than 400 mW. Three-dimensional acceleration is measured by pure digital force-balance MEMS-based accelerometers. These accelerometers have a dynamic range of more than 115 dB and a frequency response from DC to 1000 Hz with a noise floor of less than $30ng_{rms}/{\surd}Hz$. Accelerations above 0.2 g are measured by a second set of MEMS-based accelerometers, giving a full 160 dB dynamic range. This paper describes the system design and the cooperative shared-time scheduler implemented for this project. Restraints accounted for include multiple data streams, integration of multiple free agents, interaction with the asynchronous world, and hardened time stamping of accelerometer data. The prototype of the device is currently undergoing evaluation. The first array will be installed in the spring of 2006.

• Earthquakes and Structures
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• v.20 no.4
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• pp.377-388
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• 2021

Thin perforated Steel Plate Shear Walls (SPSWs) are among the most common types of seismic energy dissipation systems to protect the main boundary components of SPSWs from fatal fractures in the high-risk zones. In this paper, the cyclic behavior of the different circular hole patterns under cyclic loading is reported. Based on the experimental results, it can be concluded that a change in the perforation pattern of the circular holes leads to a change in the locations of the fracture tendency over the web plate, especially at the plate-frame interactions. Accordingly, the cyclic responses of the tested specimens were simulated by finite element method using the ABAQUS package. Likewise, perforated shear panels with a new perforation pattern obtained by implementing Topology Optimization (TO) were proposed. It was found that the ultimate shear strength of the specimen with the proposed TO perforation pattern was higher than that of the other specimens. In addition, theoretical equations using the Plate-Frame Interaction (PFI) method were used to predict the shear strength and initial stiffness of the considered specimens. The theoretical results showed that the proposed reduced coefficients relationships cannot accurately predict the shear strength and initial stiffness of the considered perforated shear panels. Therefore, the reduced coefficients should be adopted in the theoretical equations based on the obtained experimental and numerical results. Finally, with the results of this study, the shear strength and initial stiffness of these types of perforated shear panels can be predicted by PFI method.

• Advances in concrete construction
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• v.14 no.5
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• pp.317-330
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• 2022

This paper investigated computationally and experimentally the interaction here between a notch as well as a micropore under uniaxial compression. Brazilian tensile strength, uniaxial tensile strength, as well as biaxial tensile strength are used to calibrate PFC2d at first. Then, uniaxial compression test was conducted which they included internal notch and micro pore. Experimental and numerical building of 9 models including notch and micro pore were conducted. Model dimensions of models are 10 cm × 10 cm × 5 cm. Joint length was 2 cm. Joints angles were 30°, 45° and 60°. The position of micro pore for all joint angles was 2cm upper than top of the joint, 2 cm upper than middle of joint and 2 cm upper than the joint lower tip, discreetly. The numerical model's dimensions were 5.4 cm × 10.8 cm. The fractures were 2 cm in length and had angularities of 30, 45, and 60 degrees. The pore had a diameter of 1 cm and was located at the top of the notch, 2 cm above the top, 2 cm above the middle, and 2 cm above the bottom tip of the joint. The uniaxial compression strength of the model material was 10 MPa. The local damping ratio was 0.7. At 0.016 mm per second, it loaded. The results show that failure pattern affects uniaxial compressive strength whereas notch orientation and pore condition impact failure pattern. From the notch tips, a two-wing fracture spreads almost parallel to the usual load until it unites with the sample edge. Additionally, two wing fractures start at the hole. Both of these cracks join the sample edge and one of them joins the notch. The number of wing cracks increased as the joint angle rose. There aren't many AE effects in the early phases of loading, but they quickly build up until the applied stress reaches its maximum. Each stress decrease was also followed by several AE effects. By raising the joint angularities from 30° to 60°, uniaxial strength was reduced. The failure strengths in both the numerical simulation and the actual test are quite similar.

• Journal of Families and Better Life
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• v.23 no.2 s.74
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• pp.107-125
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• 2005

Each ethnic group has a different cultural background and has developed its own culture in the name of a tradition. The interaction between different cultures is ever increasing through the process of acculturation or culture contact The purpose of this study is to provide baseline information about domestic living of Korean immigrants in Australia and Australians for a larger cross-cultural study project. As the first step, the usage of domestic space and seating styles of 52 Korean households in Melbourne were analyzed. Ethnographic research was conducted, utilizing a questionnaire. The findings of this research are as follows: 1. The most popular type of Living-Dining-Kitchen arrangement was the one which the kitchen is separated from the living and dining area. The level of satisfaction was the highest when the living room, dining room, and kitchen were all separated. 2. A laundry room was indispensable for Koreans in Australia, and they wanted to dry laundry and do ironing in there. Most people were satisfied with the toilet separated from the bathroom A drain hole on the floor of the bathroom was not indispensable for most Korean-Australians. 3. Korean-Australians tend to engage in various activities in their individual rooms, and they estimated that the size of most rooms were small. They also wanted to renovate the house to expand the rooms. 4. The seating style of Korean-Australians was mostly chair-seating. Yet, they often made beds on the floor for guests, and made kimchi sitting on the floor. Also, when they were relaxing, they were using both chair-seating and floor-seating. 5. Korean-Australians were not very satisfied with the use of floor carpets because of the dust collected on the carpets, and the difficulty to clean. It may be related to their preferred floor seating style, as well. 6. Almost all Korean-Australians take off their shoes inside of the house for hygienic reasons. They had a shoes cabinet at the entrance inside of the house. 7. The most popular heating system was ducted heating. The level of satisfaction about this was moderate because hot air contains lots of dust and it makes rooms very dry. Many were using electric blankets and their desired heating system was Ondol (heated floor). 8. Korean-Australians thought that the living room was the most important place for the family, and believed it should be decorated well to entertain guests. They also pointed out that the lighting was not bright enough in general.

• Journal of Families and Better Life
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• v.24 no.1 s.79
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• pp.159-179
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• 2006

Each ethnic group has different cultural backgrounds and each culture has developed with its own traditions. The interaction between different cultures is getting more active through acculturation and cultural contacts. The purpose of this study was to compare domestic living of Korean immigrants with Australians in the form of a Cross-Cultural study. For this, usage of domestic space and seating style of 52 Korean households and 53 Australian households in Melbourne were analyzed. Ethnographic research with questionnaire was used. The results of the research were as follows. 1. The most popular type of Living-Dining-Kitchen arrangement was L+ K. D for Koreans and L. D . K for Australians. 2. A laundry room was indispensable for both and they all wanted to do ironing in there as well as dry. Both were satisfied with the type which toilet was separated from the bathroom Drain hole on the floor of the bathroom was not indispensable for most Koreans and Australians. 3. Koreans and Australians were doing various activities in living area and both were getting together around kitchen(dining) area. The particular thing of Koreans was that they were using the main bedroom with multiple purpose. 4. The seating style of Koreans and Australians belong to chair-seating style generally. But Koreans were using floor seating style in making bed for the guest and making Kimchi. Koreans and Australians were using mixed style of floor seating and chair-seating in relaxing time with watching TV, treating guest or so. 5. Koreans were not satisfied with using carpet cause of dust but Australians were satisfied with the carpet cause of warmness. 6. Most Koreans and Australians were take off shoes inside of the house. Koreans were organize shoes around the front door of the house usually and Australians were organize shoes in bedroom usually. 7. The most popular heating system was ducted heating for both. The level of satisfaction about ducted heating was low for Koreans because they though that it could contaminate air. Australians were satisfied with ducted heating because they though that this one was fit on the weather of this area. 8. Living room was the most important one for Koreans and Australians and they also thought it should be decorated well for entertaining guests. Most Koreans were estimate that the brightness of the light of the house was not enough but it was estimated to moderate for Australians on the contrary.

• Journal of the Korean Geosynthetics Society
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• v.12 no.4
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• pp.77-86
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• 2013

Laboratory pullout tests were conducted to evaluate pullout performance of steel strip reinforcements with deformed steel bars as transverse members. The steel strip reinforcement has an installation hole to assemble a deformed steel bar. Jumunjin standard sand is used to form a relative density of ground model to 80%. Frictional resistance of steel strip reinforcement without transverse member increases sharply at the initial displacement and quickly decreases with displacement. Maximum frictional resistance increases linearly as normal pressure increasing, and soil-reinforcement interaction friction angle(${\rho}_{peak}$) of a steel strip reinforcement is estimated to $14.64^{\circ}$. Passive resistance increases with displacement and converge into maximum passive resistance in most cases. Maximum passive resistance increases linearly as normal pressure increasing irrespective of shape of the steel reinforcement. Pullout force of steel strip reinforcements with installation holes or transverse members largely increases about 4 to 7 times compared to frictional resistance force of steel strip reinforcements when embedment length($L_e$) of steel strip reinforcements is 500 mm. In the case of using 2 transverse members, interference effect is observed due to the spacing of 2 transverse members and location of assembly holes and transverse members.

• Journal of the Korean Home Economics Association
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• v.43 no.9 s.211
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• pp.143-162
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• 2005

Many ethnic groups have different cultural backgrounds and each culture has developed with its own traditions. The interaction between different cultures is getting more active through acculturation and cultural contact. The purpose of this study was to provide basic data about the domestic living of Australians in order to compare with Korean immigrants in the form of a Cross-Cultural study. For this, usage of domestic space and seating style of 53 Australian households in Melbourne were analyzed. Ethnographic research with questionnaire was used. The results of the research were as follows. 1. The open plan type combining the kitchen, dining and tying areas was the most popular one for Australians and they are very satisfied with that type. 2. The laundry room has been planned traditionally and Australians demand to be able to dry their laundry and do ironing in there additionally. Most of Australians were satisfied with separated toilet and bathroom. h drain hole on the floor of the bathroom was not essential for most Australians. 3. Australians were doing various activities in the living areas and they also enjoy gelling together in the kitchen and dining areas. 4. The seating style of Australians was generally the chair-seating style. However, they sometimes made a bed for guests on the floor and watched TV and treated guests with both chair seating style and floor seating style. 5. Australians were satisfied with using carpet presumably for its warmth.6. Many Australians took off their shoes inside of the house for hygienic reason. Most people organized the shoes in the cabinet of the bedroom. 7. The most popular heating system was ducted heating for Australians and they were very satisfied with it because it was suitable for the weather in Melbourne. 8. The living room was the most important one for Australian families and they thought that it should be decorated well for entertaining guests. It was also considered that brightness of the light was enough for most Australians.

• The Journal of the Korean bone and joint tumor society
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• v.2 no.1
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• pp.1-7
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• 1996

PURPOSE : The purpose of this study is to know the ability of detecting malignant tumor tissue by Tl-201 scan, and to compare with that of Tc-99m-MIBI and Tc-99m-MDP scan. MATERIAL AND METHODS : Between February 1994 and December 1995,38 unselected patients with various bone pathologies were studied prospectively. Eighteen had malignant bone and soft tissue pathologies, while twenty had benign. All patients were studied with Tl-201, Tc-99mMIBI and Tc-99m-MDP scan prior to surgical biopsy. PICKER Prism 2000 gamma camera with high resolution parallel hole collimator was used for scanning. To avoid the interaction of isotope, the early(30min.) and delayed phase(3hrs.) of Tl-20l scan was performed first and Tc-99m-MIBI scan was performed after 30 minutes, and then Tc-99m-MDP scan 48 hours later. The scan images were visually evaluated by a blinded nuclear medicine physician. We could find true positive, true negative, false positive and false negative by the comparison of results with those of biopsy. We calculated positive and negative predictive value(%), sensitivity(%), specificity(%) and diagnostic accuracy(%) of each scan. RESULT : The results of each scan were 85.7, 100, 100, 85, 92.1% in Tl-201, 81, 94.1, 94.4, 80, 86.8% in Tc-99m-MIBI and 50, 66.7, 88.9, 20, 52.6% in Tc-99m-MDP scan. As a conclusion, Tl-201 scan was the most specific and accurate method for detecting malignant tumor tissue. Tc-99m-MIBI scan was also good for malignant tumor searching. CONCLUSION : With our results, we can use Tl-201 scan to differentiate benign from malignant tumor, and to evaluate the response of preoperative chemotherapy or radiotherapy, and to determine the residual tumor or local recurrence. For the better result, we need to have a more detail information about false positive cases and a more objective and quantitative reading technique.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.1
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• pp.92-100
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• 2018

Vortical systems are considered a main feature to sustain turbulence in a boundary layer through interaction. Such turbulent structures result in frictional drag and erosion or vibration in engineering applications. Research for controlling turbulent flow has been actively carried out, but in order to show the effect of vortices in a turbulent boundary layer, it is necessary to clarify the mechanism by which turbulent energy is transferred. For this purpose, it is convenient to demonstrate and capture phenomena in a laminar boundary layer. Therefore, in this study, the interactions of disturbed flow around a hemisphere on a flat plate in laminar flow were analyzed. In other words, a street of hairpin vortices was generated following a wake region formed after flow separation occurred over a hemisphere. Necklace vortices surrounding the hemisphere also appeared due to a strong adverse pressure gradient that brought high momentum fluid into the wake region thereby leading to an increase in the frequency of hairpin vortices. To mitigate the effect of these necklace vortices, local suction control was applied through a hole in front of the hemisphere. Flow visualization was recorded to qualitatively determine flow modifications, and hot-film measurements quantitatively supported conclusions on how much the power of the hairpin vortices was reduced by local wall suction.