• KIPS Transactions on Software and Data Engineering
• /
• v.3 no.5
• /
• pp.187-194
• /
• 2014

Prostate cancer is a malignant tumor occurring in the prostate. Recently, the repetition rate is increasing. Image inspection method which we can check the prostate structure the most correctly is MRI(Magnetic Resonance Imaging), but it is hard to apply it to all the patients because of the cost. So, they use mostly TRUS(Transrectal Ultrasound) images acquired from prostate ultrasound inspection and which are cheap and easy to inspect the prostate in the process of treating and diagnosing the prostate cancer. Traditionally, in the hospital the doctors saw the TRUS images by their eyes and manually segmented the boundary between the prostate and nonprostate. But the manually segmenting process not only needed too much time but also had different boundaries according to the doctor. To cope the problems, some automatic segmentations of the prostate have been studied to generate the constant segmentation results and get the belief from patients. In this study, we propose an average shape model to segment the prostate boundary in TRUS prostate image. The method has 3 steps. First, it finds the probe using edge distribution. Next, it finds two straight lines connected with the probe. Finally it puts the shape model to the image using the position of the probe and straight lines.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.15 no.1
• /
• pp.189-197
• /
• 2011

In the field of structural test, it is a very important factor to apply with an appropriate test jig to enhance test accuracy and efficiency. Especially in the large scale structure test, proper test apparatus scheme will reduce overall cost and time of the test project. Actuators, oil jack and UTM is generally used to evaluate the flexural capacity of the test beam. But in the case of multiple loading point or asymmetric loading of large scale test specimen, existing test method such as UTM have a difficulty in giving an accurate load. In this study new test method which is composed of existing test apparatus will be developed to improve test accuracy and economic efficiency.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.22 no.6
• /
• pp.30-36
• /
• 2018

Researches on strengthening and rehabilitation are important since structural capacity is degraded by deterioration or damage of structural members. An effective strengthening scheme such as an externally bonded Carbon Fiber Reinforced Polymers (CFRP) can improve the structural performance of a concrete structure in a cost-effective way. Therefore, many experimental studies on strengthening methods have been widely carried out. In regards to the shear strengthening of a concrete beam, variables of the experimental studies were the amount of CFRP, the angle of the strip, the width of the strip, and the interaction between the materials. However, there are insufficient researches on bi-directional CFRP layout compared to the previous researches. In this study, a total of ten concrete beams were designed and tested to evaluate the shear strengthening effect using CFRP strips. The effectiveness of strengthening was investigated based on the shear contribution of materials, strain distribution of stirrup, and the maximum shear capacity of specimens.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.7 no.3
• /
• pp.251-262
• /
• 2003

LCP(Life Cycle Profiles) of bridge structures are indispensable for the LCC(Life Cycle Cost) evaluations of bridge system. The bridge under considerations may be newly-designed one or one in service. Thus, a systematic study of LCP is essential for both reliable LCC evaluation and strategic bridge management. LCP is mainly influenced by the structural environment in nature. However, in Korea, LCC evaluation has been performed with the LCP of foreign research results or only with the pieces of professional engineers' opinion. Therefore, to alleviate the drawbacks of foreign LCP and to enhance the reliability of current LCP, LCP should be established using the available data in bridge management system(BMS). In this study, LCP along with a subset of the BMS data was investigated and several mathematical expressions were proposed and evaluated. The condition ratings of a bridge were trasformed into the numerical indices through fuzzy logics with real field data. From the numerical results, it is concluded that the mathematical LCP model of $y=\sqrt{y^2_0-at}$ is shown to be the fittest one (R=0.815) to express the condition rating varied with the age. This has been drawn from the case study of slab bridges under the similar conditions.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.16 no.1
• /
• pp.99-109
• /
• 2012

This study aimed to develop a Structural Health Monitoring System for steel beams in the manner of suggesting and verifying a theoretical formula for displacement estimation using strain gauges, and estimating the loading points and magnitude. According to the results of this study, it was found that when a load of 160kN (56% of the yield load) was applied, the error rate of the deflection obtained with a strain gauge at the point of maximum deflection compared to the deflection measured with a displacement meter was within 2%, and that the estimates of the magnitude and points of load application also showed the error rate of not more than 1%. This suggests that the displacement and load of steel beams can be measured with strain gauges and further, it will enable more cost-effective sensor designing without displacement meter or load cell. The Structural Health Monitoring System program implemented in Lab VIEW gave graded warnings whenever the measured data exceeds the specified range (strength limit state, serviceability limit state, yield strain), and both the serviceability limit state and strength limit state could be simultaneously monitored with strain gauge alone.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.20 no.4
• /
• pp.51-58
• /
• 2016

Concrete structure is a construction material with durability and cost-benefit, however the corrosion in embedded steel causes a critical problem in structural safety. This paper presents an evaluation of chloride resistance and pull-off performance with various corrosion level. For the work, OPC(Ordinary Portland Cement) concrete and GGBFS(Ground Granulated Blast Furnace Slag) concrete are prepared with normal steel. Artificially notch induced FRP Hybrid Bar is also prepared and embedded in OPC concrete and accelerated corrosion test is performed. Through the test, FRP Hybrid Bar with notch is evaluated to have insignificant effect on pull-off capacity when corroded steel shows only 21% level of pull-off capacity. Furthermore GGBFS concrete with normal steel shows over 70% level of pull-off capacity due to reduced corrosion currency.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.19 no.5
• /
• pp.67-74
• /
• 2015

RC (Reinforced Concrete) structures are considered as cost-benefit and durable however performances of structural safety and durability are degraded due to steel corrosion. Service life in RC structure is differently evaluated due to different local environmental conditions even if it is exposed to the same chloride attack. In the paper, 25 concrete cores from field investigation are obtained from 4 RC columns with duration of 3.5~4.5 years exposed to sea water. Through total chloride content measurement, surface chloride contents and apparent diffusion coefficients are evaluated. Service life of the target structure is estimated through deterministic method based on Fick's $2^{nd}$ Law and probabilistic method based on durability failure probability, respectively. Probability method is evaluated to be more conservative and relatively decreased service life is evaluated in tidal zone and splash zone over 40.0 m. Chloride penetration behavior with coring location from sea level and the present limitations of durability design method are investigated in the paper.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.17 no.4
• /
• pp.101-111
• /
• 2013

In this study, DEA (Data Envelopment Analysis) was carried out on the four bridges, which have the same extension (L=1,615m), in order to select the most superior, economical method of construction using the LCC concept of each bridge structure in the case of the Ulsan-Pohang double track railway which is scheduled to be constructed. DEA models were analyzed with the CCR model, which was designed for the evaluation of relative efficiency of each model. The initial construction costs, maintenance costs, indirect costs (user costs + indirect loss of social costs), and life cycle costs were used as input variables, and average duration was applied as the output variable. LCC was applied to calculate the input variables, and to get the costs of LCC, 100 years of period and 4.83% of real discount rate were applied, and the costs are classified into initial construction, maintenance, user, and indirect loss of social cost. The analysis results showed that the Method 2 and 3 were evaluated as the most efficient, and the other alternatives were evaluated as the following order; Method 1, the default, and Method 4.

• Journal of KIISE:Computing Practices and Letters
• /
• v.8 no.1
• /
• pp.46-61
• /
• 2002

Among the many phases involved in software development, requirements analysis phase in generally considered to play a crucial role in determining the overall software quality. Therefore, many software development companies manages the phase as one of the important phase. Especially, safety assurance through requirements analysis for safety-critical systems is quite demanding, and national and international bodies routinely require safety demonstration. Among various approaches, inspection and formal methods are generally shown to be effective. In this paper, we propose a formal verification procedure for SCR(Software Cost Reduction)-style SRS(Software Requirements Specification) using the PVS specification and verification procedure and applied this procedure to an industrial system such that a shutdown system for Wolsung nuclear power plant. This system had been verified through inspection not formal verification. The application of formal methods is rare in Korea, so it is very important to experiment about formal verification to industrial systems.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.10 no.3
• /
• pp.175-185
• /
• 2006

This study performed the optimum design of balanced and unbalanced span length bridges with many variable Girder types by using the optimum design program to minimize the cost for PSC box girder bridge of the full staging method. The objective of this study is to present tendon's application direction about complicated construction hereafter by studying about optimum tendon arrangement that is worked in each variable Girder type. This program used SUMT procedure and Kavlie's extended penalty function to allow infeasible design points in the process. Powell's direct method was used in searching design points and Gradient Approximate Method was used to reduce design hours.