• Steel and Composite Structures
• /
• v.51 no.2
• /
• pp.153-172
• /
• 2024

Due to the fast development of constructions in recent years, there has been a rapid consumption of fresh water and river sand. In the production of concrete, alternatives such as sea water and sea sand are available. The near surface mounted (NSM) technique is one of the most important methods of strengthening. Aluminum alloy (AA) bars are non-rusting and suitable for usage with sea water and sand concrete (SSC). The goal of this study was to enhance the shear behaviour of SSC-beams strengthened with NSM AA bars. Twenty-four RC beams were cast from fresh water river sand concrete (FRC) and SSC before being tested in four-point flexure. All beams are the same size and have the same internal reinforcement. The major factors are the concrete type (FRC or SSC), the concrete degree (C25 or C50 with compressive strength = 25 and 50 MPa, respectively), the presence of AA bars for strengthening, the direction of AA bar reinforcement (vertical or diagonal), and the AA bar ratio (0, 0.5, 1, 1.25 and 2 %). The beams' failure mechanism, load-displacement response, ultimate capacity, and ductility were investigated. Maximum load and ductility of C25-FRC-specimens with vertical and diagonal AA bar ratios (1%) were 100,174 % and 140, 205.5 % greater, respectively, than a matching control specimen. The ultimate load and ductility of all SSC-beams were 16-28 % and 11.3-87 % greater, respectively, for different AA bar methods than that of FRC-beams. The ultimate load and ductility of C25-SSC-beams vertically strengthened with AA bar ratios were 66.7-172.7 % and 89.6-267.9 % higher than the unstrengthened beam, respectively. When compared to unstrengthened beams, the ultimate load and ductility of C50-SSC-beams vertically reinforced with AA bar ratios rose by 50-120 % and 45.4-336.1 %, respectively. National code proposed formulae were utilized to determine the theoretical load of tested beams and compared to matching experimental results. The predicted theoretical loads were found to be close to the experimental values.

• Journal of the Korea Institute of Building Construction
• /
• v.24 no.4
• /
• pp.483-494
• /
• 2024

The purpose of this study is to develop a model for renewing old public buildings by incorporating mobility technology into them for the convenience of citizens' transportation and the enhancement of public services, and to propose support measures to improve the direction of implementation. The main contents and results of this study are as follows. First, the renewal target site was selected based on the technical considerations and evaluation criteria required for the renewal of public buildings incorporating mobility technology, and the construction was planned by analyzing the necessary mobility technology based on the size, area, and district unit plan of the selected target site. Second, the expected cost was calculated based on the construction plan and the financial support plan necessary for reflecting mobility technology was proposed. Third, the improvement plan of the building code system required for the development of public building renewal incorporating mobility technology was proposed. This study had limitations in that it could not reflect detailed construction costs due to the lack of design standards and experience, and it was difficult to identify specific problems due to the lack of specific operation methods and implementation cases.

• International Journal of Computer Science & Network Security
• /
• v.24 no.8
• /
• pp.85-104
• /
• 2024

The DNA (Deoxyribonucleic Acid) database size increases tremendously transmuting from millions to billions in a year. Ergo for storing, probing the DNA database requires efficient lossless compression and encryption algorithm for secure communication. The DNA short pattern repetitions are of paramount characteristics in biological sequences. This algorithm is predicated on probing exact reiterate, substring substitute by corresponding ASCII code and engender a Library file, as a result get cumulating of the data stream. In this technique the data is secured utilizing ASCII value and engendering Library file which acts as a signature. The security of information is the most challenging question with veneration to the communication perspective. The selective encryption method is used for security purpose, this technique is applied on compressed data or in the library file or in both files. The fractional part of a message is encrypted in the selective encryption method keeping the remaining part unchanged, this is very paramount with reference to selective encryption system. The Huffman's algorithm is applied in the output of the first phase reiterate technique, including transmuting the Huffman's tree level position and node position for encryption. The mass demand is the minimum storage requirement and computation cost. Time and space complexity of Repeat algorithm are O(N²) and O(N). Time and space complexity of Huffman algorithm are O(n log n) and O(n log n). The artificial data of equipollent length is additionally tested by this algorithm. This modified Huffman technique reduces the compression rate & ratio. The experimental result shows that only 58% to 100% encryption on actual file is done when above 99% modification is in actual file can be observed and compression rate is 1.97bits/base.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.21 no.6
• /
• pp.681-689
• /
• 2010

We will demonstrate a novel topology for the feedforward amplifier. This amplifier does not use a delay element thus providing an efficiency enhancement and a size reduction by employing a distributed element negative group delay circuit. The insertion loss of the delay element in the conventional feedforward amplifier seriously degrades the efficiency. Usually, a high power co-axial cable or a delay line filter is utilized for a low loss, but the insertion loss, cost and size of the delay element still acts as a bottleneck. The proposed negative group delay circuit removes the necessity of the delay element required for a broadband signal suppression loop. With the fabricated 2-stage distributed element negative group delay circuit with -9 ns of total group delay, a 0.2 dB of insertion loss, and a 30 MHz of bandwidth for a wideband code division multiple access downlink band, the feedforward amplifier with the proposed topology experimentally achieved a 19.4 % power added efficiency and a -53.2 dBc adjacent channel leakage ratio with a 44 dBm average output power.

• Journal of Korea Multimedia Society
• /
• v.8 no.11
• /
• pp.1496-1509
• /
• 2005

In this paper, an adaptive license plate recognition system which detects and recognizes license plate at real-time by using projected plane convolution and Decision Tree Classifier is proposed. And it was tested in circumstances which presence of complex background. Generally, in expressway tollgate or gateway of parking lots, it is very difficult to detect and segment license plate because of size, entry angle and noisy problem of vehicles due to CCD camera and road environment. In the proposed algorithm, we suggested to extract license plate candidate region after going through image acquisition process with inputted real-time image, and then to compensate license size as well as gradient of vehicle with change of vehicle entry position. The proposed algorithm can exactly detect license plate using accumulated edge, projected convolution and chain code labeling method. And it also segments letter of license plate using adaptive binary method. And then, it recognizes license plate letter by applying hybrid pattern vector method. Experimental results show that the proposed algorithm can recognize the front and rear direction license plate at real-time in the presence of complex background environments. Accordingly license plate detection rate displayed $98.8\%$ and $96.5\%$ successive rate respectively. And also, from the segmented letters, it shows $97.3\%$ and $96\%$ successive recognition rate respectively.

• Geophysics and Geophysical Exploration
• /
• v.17 no.1
• /
• pp.21-27
• /
• 2014

We analyzed response patterns of test field data acquired with new small loop electromagnetic (EM) system using three-dimensional (3D) electromagnetic modeling code. The size and shape of a conductor was adopted as experimental parameters for EM modeling to understand influencing factors of the response patterns due to a metallic object on the seafloor. Obtaining the responses for four models of difference sizes and shapes through 3D EM modeling, we confirmed that the shape of the object have a more critical factor on the response pattern than size. We also calculated "ppm" values with respect to different altitudes of the sensor and source frequencies. The modeling results show that the consistency of sensor altitude is important and imaginary part of ppm response is more sensitive than real part. We also visualized the contour map of the real and imaginary part of ppm value as a function of frequency and altitude so that we can estimate proper altitude for source frequency band of our survey system. The results of this paper are anticipated to give proper parameters in survey construction for seafloor massive sulfide deposit.

• Journal of the Korea Concrete Institute
• /
• v.17 no.3 s.87
• /
• pp.375-384
• /
• 2005

The effects of bar deformation properties on bond of steel reinforcing bars to concrete are experimentally studied to predict the bond strength. Based on the previous research about high relative rib area, bond strength between reinforcing bars and concrete can be improved by the control of rib height and spacing. But, the equations in Korean code provisions to estimate development and splice length do not include these specifications of reinforcing bars. So the purpose of this paper is to determine the effect of relative rib area to the bond strength. This paper describes 2 kinds of experimental researches. Thirty beam-end specimens were tested to investigate the effects of bar size and relative rib areas ranging from 0.112 to 0.162. And, twelve lap-splice beam specimens were tested to the same variables. Each test results are normalized and compared with the proposed equations of ACI 408 committee. The results show that bond strength is increased as bar size and the relative rib area(Rr) increase. The distribution of flexural cracks and failure aspect do not appear to be affected by $R_r$.

• Journal of KIISE
• /
• v.42 no.4
• /
• pp.496-503
• /
• 2015

Most programming languages are designed based on English. It becomes another barrier in learning programming languages in non-English speaking country. If a programming language is presented using a native language, the education cost of programming will be much cheaper and the programming itself can be much more fun. However, designing the programming languages based on native languages has not been much focused or published up to now. It is partly because the evolution of popular programming languages is so fast, and partly because the efficiency of programs is much stressed than the source code. But, the designing of programming languages based on native language is not a small issue, especially if we reflect on the education of programming. In fact, there have been significant efforts reported in the Korean programming languages so far, but it has not practically been used in the education. This paper introduces yet another Korean programming language, namely Sprout, which is concise and can be easily learned by beginners. To demonstrate the conciseness of Sprout, we have performed two experiments on Sprout. Firstly, we compared the sizes of the programs in Sprout with those in former Korean programming languages. Secondly, we compared the size of Sprout, the language itself, with those of popular programming languages such as C and Python. According to the experiments, Sprout programs are more concise to 10% on average than those in former Korean languages. Furthermore, Sprout itself is more compact to 24% on average than other popular programming languages.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.17 no.2
• /
• pp.1-9
• /
• 2013

In recent years, numerous mega-size and complex civil infrastructures have been constructed worldwide. For the more precise construction and maintenance process management of these civil infrastructures, the application of a variety of smart sensor-based structural health monitoring (SHM) systems is required. The efficient management of both sensors and collected databases is also very important. Recently, several kinds of database access technologies using Quick Response (QR) code and Augmented Reality (AR) applications have been developed. These technologies provide software tools incorporated with mobile devices, such as smart phone, tablet PC and smart pad systems, so that databases can be accessed very quickly and easily. In this paper, an AR-based structural health monitoring technique is suggested for sensor management and the efficient access of databases collected from sensor networks that are distributed at target structures. The global positioning system (GPS) in mobile devices simultaneously recognizes the user location and sensor location, and calculates the distance between the two locations. In addition, the processed health monitoring results are sent from a main server to the user's mobile device, via the RSS (really simple syndication) feed format. It can be confirmed that the AR-based structural health monitoring technique is very useful for the real-time construction process management of numerous mega-size and complex civil infrastructures.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.53 no.1
• /
• pp.97-104
• /
• 2016

Because of rapid growth of data size, the number of data storage has been increased. When using multiple data storages, a distribute file system is essential to insure the availability of data files. The power consumption is a major problem when using a distributed file system with many data storages. Previous works have aimed at reducing the energy consumption with efficient file block layout by changing some data servers into stand-by mode. The file block migration has not been seriously considered because migration causes large cost. But when we consider addition of a new data server or file, file block migration is needed. This paper formulates the minimization of data block migration as an ILP optimization problem and solves it using branch-and-bound method. Using this technique, we can maximize the number of stand-by data servers with the minimum number of file block movement. However, computation time of branch-and-bound method of an ILP optimization problem increases exponentially as the problem size grows. Therefore this paper also proposes a data block and data server grouping method to solve many small ILP problems.