• Journal of the Institute of Convergence Signal Processing
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• v.9 no.3
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• pp.213-218
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• 2008

This paper describes hardware-based high speed multimedia data reassembly processor for remote multimedia Set-Top-Box(MSTB) of interactive satellite multimedia communication system. The conventional multimedia data reassembly scheme is based on software processing of MSTB. As increasing of transmission rate for multimedia data services, the CPU load of remote MSTB is increased and reassembly performance of MSTB is limited. To provide high speed multimedia data service to end user, we proposed hardware based high speed multimedia data reassembly processor. It is implemented by using an FPGA, a PCI interface chip, and RAMs. And it is integrated in MSTB and tested. It has been confirmed to meet required all functions and processing rate up to 116Mbps.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.5 no.1 s.9
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• pp.55-63
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• 2006

Speeding is one of the major causes of traffic accidnets in urban areas. Driver feedback sign(DFS) is a traffic control device that can be used for many traffic environments including work zones, school zones, and roadways. In this paper, the effectiveness of DFS was evaluated through a field study using speed data collected from before and after study periods. In addition traffic safety improvement was also quantitatively estimated using the variance of speed data collected. Staistical test results showed that the speed difference was statistically significant, and the distribution of speed data was also shifted greatly. Therefore, it was concluded that installing the DFS in roadways might lead to unifomity of speed of traffic flow, thus, potential safety improvement might be expected.

• Structural Engineering and Mechanics
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• v.63 no.6
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• pp.809-824
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• 2017

The accurate evaluation of wind characteristics and wind-induced structural responses during a typhoon is of significant importance for bridge design and safety assessment. This paper presents an expectation maximization (EM) algorithm-based angular-linear approach for probabilistic modeling of field-measured wind characteristics. The proposed method has been applied to model the wind speed and direction data during typhoons recorded by the structural health monitoring (SHM) system instrumented on the arch Jiubao Bridge located in Hangzhou, China. In the summer of 2015, three typhoons, i.e., Typhoon Chan-hom, Typhoon Soudelor and Typhoon Goni, made landfall in the east of China and then struck the Jiubao Bridge. By analyzing the wind monitoring data such as the wind speed and direction measured by three anemometers during typhoons, the wind characteristics during typhoons are derived, including the average wind speed and direction, turbulence intensity, gust factor, turbulence integral scale, and power spectral density (PSD). An EM algorithm-based angular-linear modeling approach is proposed for modeling the joint distribution of the wind speed and direction. For the marginal distribution of the wind speed, the finite mixture of two-parameter Weibull distribution is employed, and the finite mixture of von Mises distribution is used to represent the wind direction. The parameters of each distribution model are estimated by use of the EM algorithm, and the optimal model is determined by the values of $R^2$ statistic and the Akaike's information criterion (AIC). The results indicate that the stochastic properties of the wind field around the bridge site during typhoons are effectively characterized by the proposed EM algorithm-based angular-linear modeling approach. The formulated joint distribution of the wind speed and direction can serve as a solid foundation for the purpose of accurately evaluating the typhoon-induced fatigue damage of long-span bridges.

• Korean Journal of Applied Biomechanics
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• v.21 no.5
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• pp.639-644
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• 2011

The purpose of this study was to provide quantified data on the throwing skills of world-class athletes and to analyze the kinematic variables for women shot-putters at the IAAF World Championships Daegu 2011. Three-dimensional motion analyses of the eight players who qualified for the final round were carried out to obtain the data. The Kwon3D XP program was used for image analysis of the kinematic data, which included the configurations of each joint. The following conclusions were arrived at. The throwing distance increased with an increase in the release speed, and a significant correlation (p <. 01) was observed between the throwing distance and release speed. It was also shown that players using the spin technique increased their release speed with a fast shoulder-rotation-angle speed. The release height varied with their height and showed a significant difference with the record. This showed that the release angle did not greatly influence the record for the game, but varied with their technical and physical characteristics. Therefore, an increase in release speed is required to improve the record.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.9
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• pp.1730-1738
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• 1994

Broadband code division multiple access(B-CDMA)previously proposed for personal communication services(PCS) is not suitable for high-speed data services with large variations in speed, because it is designed only for low-speed voice calls with small variations in speed. Meanwhile, hybrid intra-cell TDMA/inter-cell CDMA(Hybrid TDMA/CDMA) recently proposed could accomodate high-speed services easily because of its internal use of the TDMA scheme, but there would be much inefficiency in treating variable bit rate services due to the intrinsic properties of TDMA transmission scheme, In this paper, a media access control(MAC) protocol, called Resevation TDMA/CDMA, which uses a reservation scheme similar to the one in the packet reservation multiple access(PRMA) protocol to compensate for these shortcomings is proposed. In addition, the performance of this protocol is analyzed and compared with conventional protocols by computer simulation. According to the simulation results, it has been shown that the proposed Reservation TDMA/CDMA scheme could support various transmission rates of user data traffics easily, and it could utilize the variations of the treansmission rates in each active call more efficiently.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.11 no.1
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• pp.64-72
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• 2001

This paper is on a design of the high-speed cipher IC using IDEA algorithm. The chip is consists of six functional blocks. The principal blocks are encryption and decryption key generator, input data circuit, encryption processor, output data circuit, operation mode controller. In subkey generator, the design goal is rather decrease of its area than increase of its computation speed. On the other hand, the design of encryption processor is focused on rather increase of its computation speed than decrease of its area. Therefore, the pipeline architecture for repeated processing and the modular multiplier for improving computation speed are adopted. Specially, there are used the carry select adder and modified Booth algorithm to increase its computation speed at modular multiplier. To input the data by 8-bit, 16-bit, 32-bit according to the operation mode, it is designed so that buffer shifts by 8-bit, 16-bit, 32-bit. As a result of simulation by 0.25 $\mu\textrm{m}$ process, this IC has achieved the throughput of 1Gbps in addition to its small area, and used 12,000gates in implementing the algorithm.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.1
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• pp.103-114
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• 2023

This study collected various data of urban roadways to analyze the effect of travel speed change, and a GRU-based short-term travel speed prediction model was developed using such big data. The baseline model and the double exponential smoothing model were selected as comparison models, and prediction errors were evaluated using the RMSE index. The model evaluation results revealed that the average RMSE of the baseline model and the double exponential smoothing model were 7.46 and 5.94, respectively. The average RMSE predicted by the GRU model was 5.08. Although there are deviations for each of the 15 links, most cases showed minimal errors in the GRU model, and the additional scatter plot analysis presented the same result. These results indicate that the prediction error can be reduced, and the model application speed can be improved when applying the GRU-based model in the process of generating travel speed information on urban roadways.

• Journal of the Korean Solar Energy Society
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• v.32 no.2
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• pp.95-104
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• 2012

This study purposed to predict wind energy for small size wind power generators at 50m above the ground in each area using mean wind speed data for 10 minutes collected from 2001 to 2011 by meteorological data in large cities having over 60% of 15 story (50m) or higher apartments including Seoul, Daejeon, Gwangju and Daegu representing the inland region, and Busan, Incheon and Ulsan representing the coastal region. In the results of analysis, we confirmed close agree ment between observatory weather data and probability density distribution obtained using Weibull's parameters, and this suggests that Weibull's parameter is applicable to the estimation of wind energy. Hourly output energy using the mean wind speed for 10 minutes and output energy obtained from Weibull's parameter showed an error less than 5%, and thus it was found that wind energy can be evaluated using Weibull's modulus.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.8
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• pp.1777-1781
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• 2011

Tosin backplane system design of this study (Backplane) from the HSTL (High-Speed Transceiver Logic) characteristics of the transmit and receive data using the HSPICE simulations and the actual implementation on the FPGA Data transmission characteristics were described by comparing the simulation results. Simulation and measurement criteria for point to point data transmission characteristics of wire length possible to send and receive data about the speed limits were reviewed. Measured point to point connection to send and receive signals at terminal velocity, the factors that affect the electrical noise around the wire length and showed a very important role.

• Journal of Biosystems Engineering
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• v.12 no.3
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• pp.7-16
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• 1987

This study was carried out to develop a microcomputer-based data acquisition and control system which was able to collect the data of engine performance test automatically and control the speed and load of the engine. The results of the study are summarized as follows: 1. The signal processing devices, which were able to measure cylinder pressure, coolant temperature, compositions of exhaust gas, fuel consumption, engine rpm and torque etc., were developed. The results of calibration showed that all of devices had high accuracy ranging from 0.3% to 0.69% respectively. 2. The PIA (peripheral interface adapter) for interfacing digital signal and PTM (programmable timer module) for displaying real time every 0.0408 sec were designed and developed. 3. An engine-speed control system using a stepping motor and driver was developed. The control system had the stability, and faster settling time than the manual control system. 4. The automatic control system of electrical dynamometer, which was able to control the speed and load of dynamometer, was developed with a SSD (shackleton system driver) and D/A converter. 5. The computer programs, which were able to collect and process the data of engine tests, were developed using both the machine language and BASIC.