• Structural Engineering and Mechanics
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• 제69권6호
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• pp.677-691
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• 2019

In recent years, interest is growing in the engineering community on the experimental assessment and the theoretical prediction of the out-of-plane (OOP) seismic response of unreinforced masonry (URM) infills, which are widespread in Reinforced Concrete (RC) buildings in Europe and in the Mediterranean area. In the literature, some mechanical-based models for the prediction of the entire OOP force-displacement response have been formulated and proposed. However, the small number of experimental tests currently available has not allowed, up to current times, a robust and reliable evaluation of the predictive capacity of such response models. To enrich the currently available experimental database, six pure OOP tests on URM infills in RC frames were carried out at the Department of Structures for Engineering and Architecture of the University of Naples Federico II. Test specimens were built with the same materials and were different only for the thickness of the infill walls and for the number of their edges mortared to the confining elements of the RC frames. In this paper, the results of these experimental tests are briefly recalled. The main aim of this study is comparing the experimental response of test specimens with the prediction of mechanical models presented in the literature, in order to assess their effectiveness and contribute to the definition of a robust and reliable model for the evaluation of the OOP seismic response of URM infill walls.

• 대한유전성대사질환학회지
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• 제6권1호
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• pp.24-31
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• 2006

Purpose : The Ministry of Health and Social Affairs adopted newborn screening for the low-income families in 1991 and expanded in 1997 to cover all newborns. At the beginning of the program 6 diseases were selected for screening but the number of screening items had been reduced to two (congenital hypothyroidism and phenylketonuria) from the year 1995. Now, the government program has a fifteen year history. The purpose of this study was to analyze results of neonatal screening tests and prevalence at birth of phenylketonuria and congenital hypothyroidism in Korea. Methods : The results of neonatal screening tests were collected from public health centers during 15 years from 1991 to 2005. These data were analyzed for number of tested newborns and prevalence at birth of the inborn errors of metabolism. Results : Neonatal screening test for inborn error of metabolism was performed for 3,707,773 newborns for 15 years. Among newborns who were screened 718 congenital hypothyroidisms and 86 phenylketonurias were detected, and these presented an prevalence at bith of congenital hypothyroidism 1/5,164 and that of phenylketonuria 1/43,114. The total prevalence of two diseases was 1/4,612. Conclusion : National screening program should be expanded to include all items of screening tests for whole newborns and established correct prevalence of other inherited metabolic diseases in Korea.

• 제어로봇시스템학회논문지
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• 제19권6호
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• pp.534-539
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• 2013

Recently, the number of vehicles equipped with cameras that are generally used to recognize surroundings is increasing. For robust recognition, a huge amount of tests under various environments are performed. Furthermore, the installation position or orientation of the camera is also changed depending on the vehicle. This change also accompanies many tests. Correspondingly, a large cost and a great deal of manpower are required to perform these tests. This paper proposes a method to cut these costs while conducting enough tests through the construction of a database of videos and a geometric transformation of images.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 봄 학술발표회 논문집
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• pp.379-386
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• 2001

Piled raft foundations are usually used to reduce total and differential settlements of superstructures. In the piled raft foundations, the raft is often on its own able to provide adequate bearing capacity and only few widely spaced piles are added to the foundation to keep settlements be1ow a certain limit. In this paper, experimental studies on the load sharing ratio between piles and raft are carried out. Also, for evaluating the application of optimum design technique using a genetic algorithm, optimal locations of files are compared with the results of laboratory model tests. from tile results of laboratory model tests, there are found that the load sharing ratio between files and raft is depended on the number of piles and stiffness of raft, and the optimal locations of piles became concentrated on the middle of rafts. From these results of laboratory model tests, the optimum technique using a genetic algorithm is acknowledged to the application in the piled raft.

• Journal of the Korean Statistical Society
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• 제26권2호
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• pp.171-180
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• 1997

Effects of order misspecification on statistical behavior of unit root tests are studied. We derive the limiting distributions of the Dickey-Fuller test statistics whose numerators are of the form c .int. W dW + .kappa. where W is a standard Brownian motion on [0, 1] and c is a real number. The term .kappa. is a major consequence of order misspecification and its explict expression is derived. Based on an analysis of .kappa., effects of order misspecification on unit root tests for AR(2), ARMA(1, 1), and AR(3) models are investigated.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.672-680
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• 2005

There are a lot of reasons to use In-place tests. Construction schedules often require that operations such as form removal, post-tensioning, termination of curing, and removal of reshores be carried out as early as possible. To enable these operations to proceed safely as soon as possible requires the use of reliable in-place tests to estimate the in-place strength. In-place test results are not reliable for engineering judgment. These results should be interpreted and correlated to standard compressive strength, based on the test method. In this paper some of these test procedures and their limitations are discussed. In this study we will go on for Rebound number, Pullout, Ultrasonic pulse velocity, and Cast-in-place cylinder methods which are most useful methods in the Asia.

• 한국안전학회지
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• 제9권2호
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• pp.18-25
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• 1994

In this thesis, the fatigue tests were performed on a series of reinforced concrete to Investigate the variation of strength and the safety of reinforced concrete structures under fatigue load. The specimens were of the same rectangular cross-section, of effective height 24cm and width 30cm and their span was 330cm. The three point loading system is used in the fatigue tests. In these tests, the fracture mode of reinforced concrete structures under fatigue load, relationship between the repeated loading cycles and the mid-span displacement of the specimens were observed. According to the test results, the following fatigue behavior of reinforced concrete specimens were observed. By increasing of the number of repeated loading cycles, the mid-span displacement became greater, however the Incremental amounts of the displacement were reduced. It could be also known that the inelastic strain energy of the doubly reinforced rectangular beams was larger than that of the singly reinforced rectangular beams as increasing the number of repeated loading cycles. Compliance of reinforced concrete structures tended to be reduced as increasing the repeated loading cycles, and the compliance of the doubly reinforced rectangular beams was generally smaller than that of the singly reinforced rectangular beams. Based on the above investigation, it could be concluded that the doubly reinforced rectangular beams under fatigue load were more efficient to resist the brittle fracture than the singly reinforced rectangular beams.

• Advances in concrete construction
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• 제11권5호
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• pp.397-407
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• 2021

This paper investigates the optimal sensor placements and capabilities of this procedure for dynamic characteristics identification of arch dams. For this purpose, a prototype arch dam is constructed in laboratory conditions. Berke arch dam located on the Ceyhan River in city of Osmaniye is one of the highest arch dam constructed in Turkey is selected for field verification. The ambient vibration tests are conducted using initial candidate sensor locations at the beginning of the study. Enhanced Frequency Domain Decomposition and Stochastic Subspace Identification methods are used to extract experimental dynamic characteristics. Then, measurements are repeated according to optimal sensor locations of the dams. These locations are specified using the Effective Independence Method. To determine the optimal sensor locations, the target mode shape matrices which are obtained from ambient vibration tests of the selected dam with a large number of accelerometers are used. The dynamic characteristics obtained from each ambient vibrations tests are compared with each other. It is concluded that the dynamic characteristics obtained from initial measurements and those obtained from a limited number of sensors are compatible with each other. This situation indicates that optimal sensor placements determined by the Effective Independence Method are useful for dynamic characteristics identification of arch dams.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.392-403
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• 2010

In this study, a new methodology by using the X-ray CT scan is proposed for estimating void ratio of very fine clayey soil. Since the particle size of the clay is too fine to calculate the volume of void inside the clays, CT scanning tests with a number of clay specimens that were artificially set to have various designated void ratios have been carried out. From the tests, a relationship between the CT values and void ratios is given to be used for estimating the invisible void ratio of very fine clay from a representative CT value scanned. The linear relationship was able to be acquired finally. It is expected that micro X-ray CT scanning can be capable of capturing the void ratio of very fine soils without any errors inherent in the conventional specific gravity tests.

• The Journal of Asian Finance, Economics and Business
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• 제8권10호
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• pp.297-303
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• 2021

The performance of the retail industry in a country, which simultaneously reflects the demand for retail space, is significantly influenced by the macroeconomic environment of said country. However, in the case of Malaysia, studies regarding this issue are limited. Therefore, this paper aims to identify the macroeconomic determinants of the demand for retail space in shopping centers in Malaysia through the study of six variables: per capita income, private expenditure, inflation rate, interest rate, total population, and the number of tourists arrival. The nexus between these variables and the demand for retail space in shopping centers were examined by cointegration and causality tests, and regression analysis using quarterly data for the period 1993Q1 to 2016Q4. The results from bivariate cointegration tests indicate that inflation rate, interest rates, population size, and the number of tourists arrival have significant long-run relationships with the demand for retail space of Malaysian shopping centers. Meanwhile, the Granger causality tests show that only population size can cause the demand for shopping centers' retail space. Finally, the results from the regression analysis revealed that income per capita, private expenditure, interest rates, and population are the variables that significantly influence the demand for the retail space of the Malaysian shopping centers.