• Journal of the Korea institute for structural maintenance and inspection
• /
• v.28 no.1
• /
• pp.98-106
• /
• 2024

Due to advancements in construction technology and analytical tools, an increasing number of cable-stayed bridges have been designed and constructed in recent years. A cable is a structural element that primarily transmits the main load of a cable-stayed bridge and plays the most crucial role in reflecting the overall condition of the entire bridge system. In this study, a vision-based method was applied to estimate the tension of the stay cables located at a long distance. To measure the response of a cable using a vision-based method, it is necessary to install feature points or targets on the cable. However, depending on the location of the point to be measured, there may be no feature points in the cable, and there may also be limitations in installing the target on the cable. Hence, it is necessary to find a way to measure cable response that overcomes the limitations of existing vision-based methods. This study proposes a method for measuring cable responses by utilizing the characteristics of cable shape. The proposed method involved extracting the cable shape from the acquired image and determining the center of the extracted cable shape to measure the cable response. The extracted natural frequencies of the vibration mode were obtained using the measured responses, and the tension was estimated by applying them to the vibration method. To verify the reliability of the vision-based method, cable images were obtained from the Hwatae Bridge in service under ambient vibration conditions. The reliability of the method proposed in this study was confirmed by applying it to the vibration method using a vision-based approach, resulting in estimated tensions with an error of less than 1% compared to tensions estimated using an accelerometer.

• Structural Engineering and Mechanics
• /
• v.90 no.6
• /
• pp.611-633
• /
• 2024

This study intends to investigate the response of multi-cell (MC) beams to flexural loads in which the primary reinforcement is composed of both metallic and non-metallic materials. "Multi-cell" describes beam sections with multiple longitudinal voids separated by thin webs. Seven reinforced concrete MC beams measuring 300×200×1800 mm were tested under flexural loadings until failure. Two series of beams are formed, depending on the type of main reinforcement that is being used. A control RC beam with no openings and six MC beams are found in these two series. Series one and two are reinforced with metallic and non-metallic main reinforcement, respectively, in order to maintain a constant reinforcement ratio. The first crack, ultimate load, deflection, ductility index, energy absorption, strain characteristics, crack pattern, and failure mode were among the structural parameters of the beams under investigation that were documented. The primary variables that vary are the kind of reinforcing materials that are utilized, as well as the kind and quantity of mesh layers. The outcomes of this study that looked at the experimental and numerical performance of ferrocement reinforced concrete MC beams are presented in this article. Nonlinear finite element analysis (NLFEA) was performed with ANSYS-16.0 software to demonstrate the behavior of composite MC beams with holes. A parametric study is also carried out to investigate the factors, such as opening size, that can most strongly affect the mechanical behavior of the suggested model. The experimental and numerical results obtained demonstrate that the FE simulations generated an acceptable degree of experimental value estimation. It's also important to demonstrate that, when compared to the control beam, the MC beam reinforced with geogrid mesh (MCGB) decreases its strength capacity by a maximum of 73.33%. In contrast, the minimum strength reduction value of 16.71% is observed in the MC beams reinforced with carbon reinforcing bars (MCCR). The findings of the experiments on MC beams with openings demonstrate that the presence of openings has a significant impact on the behavior of the beams, as there is a decrease in both the ultimate load and maximum deflection.

• The Journal of Engineering Geology
• /
• v.34 no.2
• /
• pp.249-262
• /
• 2024

Retaining walls are widely used in the construction of underground structures. This study reviews the stability of the high-strength joint buried pile method at a site in Korea. [Consider giving details of the location.] The method is assessed by considering the amount of ground settlement, as calculated by finite element analysis and measured at the site. Comparison of the measured and numerical results confirmed the method's stability and field applicability. Settlement of 13.42~13.65 mm was calculated for seven cross-sections [The Abstract should be comprehensible without reference to the main text. The labels A-A' to G-G' should not be introduced here without explanation.] using numerical analysis, and the measured settlement reached a maximum of 2.00 mm. The observed differences and variations [Please state what differed/varied.] did not exceed the design expectations in any section. Instruments installed at the back of the excavation area were used to assess the conditions. An underground gradient meter recorded a cumulative horizontal displacement of between -0.40 and 0.60 mm, and an underground water meter recorded slight displacements of between -0.21 and 0.28 m compared with the initial measurements. A surface settlement meter observed very little movement, with a maximum of -2.00 mm compared with the initial measurement, thereby confirming the establishment of a stable state within the management criteria.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.26 no.3
• /
• pp.169-189
• /
• 2024

In the current work, a series of three-dimensional finite element analyses have been carried out to understand the behaviour of pre-existing single piles and pile groups to adjacent Shield TBM tunnelling by considering various reinforcement conditions. The numerical modelling has analysed the effect of the pile cutting, ground reinforcement and pile cap reinforcement. The analyses concentrate on the ground settlements, the pile head settlements, the axial pile forces and the shear stress transfer mechanism at the pile-soil interface. In all cases of the pile tips supported by weathered rock, the distributions of shear stresses presented a similar trend. Also, when the pile tips were cut, tensile forces or compressive forces were induced on the piles depending on the relative positions of the piles. Furthermore, when the pile tips are supported by weathered rock, approximately 70% of the load is supported by surface friction, and only the remaining 30% is supported by the pile tip. Furthermore the final settlement of the piles without reinforcement showed approximately 70% more settlement than the piles for which ground reinforcement is considered. It has been found that the ground settlements and the pile settlements are heavily affected by the pile cutting and reinforcement conditions. The behaviour of the single pile and group piles, depending on the pile cutting, conditions of ground and pile cap reinforcement, has been extensively examined and analysed by considering the key features in great details.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.18 no.2
• /
• pp.73-77
• /
• 2014

Purpose Find out about the significance of the GFR values calculated by the kidney depth is measured by comparing the values obtained for kidney depth was measured GFR in the CT image kidney depth and is calculated by Tonnesen law in $^{99m}Tc$-DTPA dynamic kidney scan with each applies. Materials and Methods Among patients with normal value (75~120 mL/min) computed GFR conducted of dynamic renal scan to visit from February 2013 to February 2014 and donor GFR values in patients with normal value. The mean age was 46.9 years with 14 men 13 females. We used abdomen CT image which checked before conducting dynamic Kidney scan for measuring the depth of kidney. We only used CT image that contains renal hilum and measured outermost front of the kidney from the skin surface (a) and the final surface (b) caculated the average depth of [(a + b) / 2] respectively. Using the same ROI in order to limit the change in GFR values by the other additional element was set before and after the depth value was excluded from the GFR falls kidney disease. Results Using Tonnesen law the average value was caculated 5.94 cm from the right kidney 5.90 cm from the left kidney. It was 6.83 cm, 8.71 cm in the left kidney and the right kidney average value of the depth measured on the basis of the CT image. The respective increase in left kidney 0.93 cm and right kidney 2.77 cm calculated on the basis of CT image actually measured values. GFR was calculated as the average depth of the subject calculated by the method Tonnesen $83.3{\pm}9.79mL/min$. $98.6{\pm}14.07mL/min$ GFR was applied to calculate the average depth of the subjects using the CT image, is the difference appears 15.26 mL/min was increased after seting up depth value, P value was less than 0.01 which is significant. Conclusion The difference between GFR before-after setting up depth value cause that the different of depth value. Is a measured depth of the extension value of the calculated estimates Whereas Tonnesen kidney depth method is to use in calculating the value of GFR in a typical dynamic elongation test depth derived using the CT image depth. Is thought to be able to calculate more accurately the GFR value by the distance to the center of kidney more accurately measured in the skin thereby.

• Analytical Science and Technology
• /
• v.15 no.5
• /
• pp.417-426
• /
• 2002

Inductively Coupled Plasma Dynamic Reaction Cell Quadrupole Mass Spectrometry (ICP-DRC-QMS) was characterized for the detection of the six naturally occurring calcium isotopes. The effect of the operating conditions of the DRC system was studied to get the best signal-to-noise ratio. This experiment shows that the potentially interfering ions such as $Ar^+$, ${CO_2}^+$, ${NO_2}^+$, $CNO^+$ at the calcium masses m/z 40, 42, 43, 44 and 48 were removed by flowing $NH_3$ gas at the rate of 0.7 mL/min $NH_3$ as reactive cell gas in the DRC with a RPq value (rejection parameter) of 0.6. The limits of detection for $^{40}Ca$, $^{42}Ca$, $^{43}Ca$, $^{44}Ca$, and $^{48}Ca$ were 1, 29, 169, 34, and 15 pg/mL, respectively. This method was applied to the determination of calcium in synthetic food digest samples (CCQM-P13) provided by LGC for international comparison. The isotope dilution method was used for the determination of calcium in the samples. The uncertainty evaluation was performed according to the ISO/GUM and EURACHEM guidelines. The determined mean concentration and its expanded uncertainty of calcium was ($66.4{\pm}1.2$) mg/kg. In order to assess our method, two reference samples, Riverine Water reference sample (NRCC SLRS-3) and Trace Elements in Water reference sample (NIST SRM 1643d), were analyzed.

• Journal of Korea Spatial Information System Society
• /
• v.2 no.2 s.4
• /
• pp.5-23
• /
• 2000

Since 1995, national and local governments have competitively initiated many and large GIS projects and audit for the projects becomes an important issue. So far, the audit in the Information Technology(IT) area has tried to deal with the issue but ineffectiveness has been found for the successful GIS project management. Effective auditing is a critical element for the project management. In order to establish a proper audit model for the GIS projects and to promote auditing activities in the projects, this study constructs two hypotheses and tries to prove them. The hypotheses are as follows : 1) For a good audits model for GIS, unique characteristics of a GIS project audit items and the scope of the audit need to be identified. 2) The scope of audit needs to be classified according to the requests from tasks in the projects. To prove the hypotheses, this study analyzes positive aspects of audit in IT and construction projects, clarifies the audit items in GIS projects by comparing with them, and classifies the scope of the GIS audit based on various types of GIS projects. As a results, 5 types of the GIS audit are identified : (1) audit for project management, (2) audit focused on IT, (3) audit characterized by GIS technologies, (4) GIS database audit and (5) consulting services for critical problems in the projects. In addition, 4 criteria in classifying the GIS projects are suggested for the GIS audit. The 4 criteria are domain, scope, duration, and GIS applications technologies. Especially, GIS technology considered in this study includes GIS software, methodologies for GIS development, GIS database and quality control of GIS data, which are not usually reflected in the existing studies about in GIS audit. Because the GIS audit depends on a type of GIS projects, scopes of the audit can be flexibly reconstructed in accordance with the types of GIS projects. This is a key to effective and realistic audit for the future GIS projects. Strategies for effective GIS audit are also proposed in terms of the following: GIS project management, goal establishment in each audit stage, documentation from GIS audit, timing strategies for intensive GIS audit, and designing team structure.

• Management & Information Systems Review
• /
• v.33 no.1
• /
• pp.191-217
• /
• 2014

The Purpose of this study is to find the effect factors of R&D investment in SMEs which plays an important role in the national economy, and the differences of the effect factors by the type of SMEs. The subject of this study is about 3,400 SMEs mentioned in "The survey of technical statistics on SMEs in 2007" by Korea Federation of Small and Medium Business. The effect factors are related with the size of business, the infrastructure of R&D and the activities of R&D which have been studied by many researchers. The methods of analysis are regression analysis, moderating effect analysis and the software package used is SPSS 12.0. The results of the study are as fallow. First, it was found that unlike in previous studies which show the effect of the elements of business's size, research infrastructure, research activities on R&D investment, one element alone can't be considered for meaningful result but the various elements have effect on R&D investment at the same time. In other words, the number of employees and the sales as the elements of business's size, the ratio of researchers, the technical ability, the ratio of equipment possession and the intellectual properties as the elements of R&D infrastructure, the activity of ideas and joint research as the elements of R&D activities have positive(+) effect, whereas the participation of CEO in the activity of R&D as the elements of R&D activities activity has negative(-) one. The number of employees, the ratio of researchers, and the sales had relatively high influence whereas equipment possession, technical ability, intellectual properties, the participation of CEO in the research, the activity of idea, joint research had relatively low influence. Next, it was also found that there are differences of the effect factors over the types of SMEs. SMEs were classified into 19 types by eight criteria such as start-ups and existing business by business age; small business and medium business by size; manufacturing business and service business by product type;independent business and subcontractor business by dealing type; businesses in the entering, growing, maturing and restructuring stage by growth stage; businesses with low, medium and high technology by technological level; pioneering business and non-pioneering business by industrial type; and businesses with state-of-the-art technology and non-advanced business by the level of business activities. The meaning of this study lies in the fact that it found the various effect factors should be considered at the same time when conducting study on SMEs' R&D investment, and the differences by the type should be acknowledged. This study surpassed the limitations of the previous studies which focused on a couple of factors and types. This study result can also be considered for other studies on achievement, organization, marketing and others. Moreover, it shows that a differential policy by business type is needed when formulating SME policy.

• Journal of the Korean Wood Science and Technology
• /
• v.15 no.2
• /
• pp.1-15
• /
• 1987

This experiment was undertaken for the purpose of investigation of relative durability about thirty sorts of the korean native wood and nine sorts of the wood destroying fungi Polystictus versicolor, Irpex consors. Poria vaporaria, Merulius lacrymans, Schizophyllum commune, Trametes pini, Lenzites betulina, Paxillus panuoides by means of a laboratory methods. The results obtained are; (from the table 2 to 10) 1. By measuring the percentage of loss in weight with regard to Polystictus versicolor, the sap wood contained in Junipeus chinesis was calculated at 18.2%, therefore it is much higher durability than any others and the sap wood contained in Pinus densiflora was measured at 44.10%, therefore it is much lower durability than any others. 2. By measuring the percentage of loss in weight with regard to Irpex consors, the heart wood contained in Butula schmidtii was calculated at 1.23%, therefore durability is very high and the heart wood contained in Quercus dentata was calculated at 26.79%, therefore durability is very low. 3. By measuring the percentage of lass in weight with regard to Lenzites betulina, the heart wood contained in Betula schmidtii was calculated at 5.33%, therefore it is much higher durability than any others and the sap wood with regard to Abies holophylla was measured at 45.48%, therefore durability is very low. 4. By measuring the percentage of loss in weight with regard to Poria vaporaria, the sap wood contained in Fraxinus rhynchophylla was calculated at 5.57%, therefore durability is very high and the sap wood contained in Paulownia coreana was calculated at 35.6%, therefore it is much lower durability than any others. 5. By measuring the percentage of loss in weight with regard to Merulius lacrymans, the heart wood contained in Castanea crenata was measured at 0.09% and in the next place, the heart wood contained in Abies holophylla calculated at 0.15% did not decay almost and the sap wood contained in Cornus controversa was measured at 32.88%, therefore it is lower durability than any others. 6. By measuring the percentage of loss in weight with regard to Schizophyllum commune, the sap wood cantained in Junipensis chinensis was calculated at 1.09%, therefore durability is very high and the sap wood contained in Populus deltoides was calculated at 36.87%, it is much lower durability than any others. 7. By measuring the percentage of loss ill weight with regard to Trametes pini, the sap wood contained in Robinia pseudo-acacia was calculated at 1.33%, therefore durability is very high and the sap wood contained in Comus controversa was calculated at 33.19%, it is much lower durability than any others. 8. By measuring the percentage of loss ill weight with regard to Paxillus panuoides. the heart wood contained in Zelkova serrata was calculated at 1.73%, therefore durability is very high and the sap wood contained in Populus deltoides was calculated at 42.30%, therefore durability in very low. 9. By measuring the percentage of loss in weight with regard to Dardalea quercina, the heart wood contained in Castanea crenata was calculated at 0.92%, therefore durability is very high and the sap wood contained in Cornus controversa was calculated at 32.00% therefore durability is very low. The above results are summarized as follows 1. Durability between the heart wood and the soft wood find that it is nonsignificant, while durability is higher heart wood than sap wood. 2. Special sorts including in the element like Castanea cenata, Robinia pseudo-acacia, Juniperus chinensis and heart wood like Betula schmiditii and Styrax obasia are highly durable and soft wood like Cornus controversa, Populus davidiana, Salix koreensis, Celtis jessensis are lowly durable in general. 3. Among the wood destroying fungi Paxillus panuoides is highly durable and as follows. Poria vaporaria, Lenzites betulina and the Daedalea quercina is less in general and Irpex consors, Mersulius lacrymans are a middle degree.

• Korean Journal of Food Science and Technology
• /
• v.29 no.3
• /
• pp.502-508
• /
• 1997

Rice bran dietary fiber extract, which was obtained after termamyl treatment of defatted rice bran contained $27.3{\sim}30.5%$ protein, $49.7{\sim}54.1%$ insoluble dietary fiber, and $1.9{\sim}2.7%$ soluble dietary fiber. Extrusion decreased the insoluble dietary fiber content but increased the soluble dietary fiber content, while roasting did not. Influence those content. Each mineral element content was depended upon heat processing method. Extrusion increased the water binding capacity and L value, while roasting reduced the water binding capacity and L value. Scanning electron microscopy showed damaged cell walls for extruded sample compared to roasted one which had fully collapsed cell walls. The increase of water absorption, developing time, and stability and the of MTI of wheat flour-dietary fiber extract composites with addition of dietary fiber extract were observed by Farinograph. Rice bran dietary fiber extract had an effect on the bread making resulting in increase of bread weight and color of crumb and crust, and decrease of bread volume and texture. As a result of sensory evaluation, appearance, texture, overall acceptability were significantly different from control but flavor and taste were not different significantly up to 6% level. Heat treated samples had differences in mean values, but not significant differences statistically.