• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.43 no.4
• /
• pp.525-533
• /
• 2023

Due to the topographical characteristics of Busan, which has many mountainous areas, there is a shortage of available land, and even the Gyeongbu Line railroad crosses the city center, hindering the disconnection of living areas and urban development. Accordingly, the need for multi-dimensional development has been raised to secure land, and recently, interest has been increasing in connecting cities divided by the undergroundization of the Gyeongbu Line railway and making efficient use of land. In this study, the development type was analyzed through the case of multi-dimensional development of land, and the development direction for each three-dimensional development type was set based on the results of the multi-dimensional development of four areas (Sasang Station, Gupo Station, Gaya Station, and Busanjin Station). In addition, reflecting the regional characteristics of the target area and the ongoing urban regeneration project, we will propose a design plan for horizontal and vertical space utilization of the railway site through multi-dimensional development through the efficient land use.

• Journal of the Korea Society for Simulation
• /
• v.18 no.3
• /
• pp.73-82
• /
• 2009

Due to the many advantages including low price, low power consumption, and miniaturization, the CMOS camera has been utilized in many applications, including mobile phones, the automotive industry, medical sciences and sensoring, robotic controls, and research in the security field. In particular, the 360 degree omni-directional camera when utilized in multi-camera applications has displayed issues of software nature, interface communication management, delays, and a complicated image display control. Other issues include energy management problems, and miniaturization of a multi-camera in the hardware field. Traditional CMOS camera systems are comprised of an embedded system that consists of a high-performance MCU enabling a camera to send and receive images and a multi-layer system similar to an individual control system that consists of the camera's high performance Micro Controller Unit. We proposed the SL-AVS (Small Size/Low power Around-View System) to be able to control a camera while collecting image data using a high speed synchronization technique on the foundation of a single layer low performance MCU. It is an initial model of the omni-directional camera that takes images from a 360 view drawing from several CMOS camera utilizing a 110 degree view. We then connected a single MCU with four low-power CMOS cameras and implemented controls that include synchronization, controlling, and transmit/receive functions of individual camera compared with the traditional system. The synchronization of the respective cameras were controlled and then memorized by handling each interrupt through the MCU. We were able to improve the efficiency of data transmission that minimizes re-synchronization amongst a target, the CMOS camera, and the MCU. Further, depending on the choice of users, respective or groups of images divided into 4 domains were then provided with a target. We finally analyzed and compared the performance of the developed camera system including the synchronization and time of data transfer and image data loss, etc.

• Science of Emotion and Sensibility
• /
• v.20 no.2
• /
• pp.137-148
• /
• 2017

The present study examined the effect of stimulus contrast and color on detection of a target embedded in streams of letters. In Experiment 1, each trial displayed four rapid serial visual presentation (RSVP) streams of letters (i.e., multi-RSVP), and each stream occupied one of four different locations. Each frame in the RSVP stream had four white distractors at the locations except one frame where a dim grey target was displayed at a location with three white distractors at the remaining locations. In the low-visibility target condition, the target's grey color was slightly darker than the background grey whereas much dimmer in the high-visibility condition. Participants were asked to report presence of a predesignated target as quickly and accurately as possible upon its detection in each trial, and their target detection turned out more accurate and quicker in the high-visibility than the low-visibility condition. In Experiment 2, the same RSVP displays and task as Experiment were used, but the grey target letters in the high-visibility condition were replaced with those of distinct chromatic colors. Participants detected target presence more accurately in the high-visibility condition, but the reaction time did not differ between the visibility conditions. The results indicate that higher stimulus contrast as well as distinct color can improve perception of a target stimulus displayed among visually-demanding background, but also suggest that stimulus contrast may play a more substantial role for such perceptual improvement.

• Progress in Medical Physics
• /
• v.14 no.2
• /
• pp.99-107
• /
• 2003

This study was performed to prepare the verification film for localizing beam-target position with the Photon Knife radiosurgery system (PKRS) using linear accelerator(Mitsubishi, Model ML-15MDX). We developed a laser calibration system using a reticle of transparent lucite to detect Inlet and outlet beams. We verified fixation of the second collimator with film mounted on a holder in the shape of an octagon block 5cm apart from the isocenter. The film was exposed to photon beams of linear accelerator at an interval of 45 degrees during the gantry movement. There were no shifts in the beam of the second collimator during gantry movement. We used a position marker which is designed a head-shaped small lead block and a 10 mm in diameter of steel bead in the plastic tube. The position marker helped to verify the beam directions with patient position in multi-arc and trans-multi-arc of PKRS The verification of beam alignments showed an average 0.8$\pm$0.26 mm discrepancy in LINAC-gram images of PKRS. In our study, the couch movement was $\pm$5 mm laterally, while it shook $\pm$ 2 mm toward the couch axis. The couch, however, was immediately returned to the initial site after shaking. Thus, we postulate that the beam-target position(s) should be verified with LINAC-gram in a stereotactic radiosurgery system to achieve the accuracy of beam-target alignment.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.46 no.1
• /
• pp.24-31
• /
• 2009

In this paper, the new technique combing power control with Pre-FFT beamforming is proposed for MIMO(multi-input multi-output)-OFDM(orthogonal frequency division multiplexing) system. As combining the proposed power control with beamforming, we can iteratively control the transmittingpower and update the weight of beamformer together. And then, the beam is formed toward the desired direction and SNIR of each subcarrier is converged to target SNIR. Therefore, the performance of MIMO-OFDM system is very improved. BER performance improvement of the proposed approach is investigated through computer simulation by combining power allocation algorithm with MIMO-OFDM system using Pre-FFT beamformer

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.11
• /
• pp.5447-5451
• /
• 2012

This paper presents a pattern-switchable microstrip patch antenna with loop structure. The loop structure for switchable radiation beam pattern is connected with feeding line of the microstrip patch antenna. As changing switch on/off state, the radiation beam pattern can be changed. The target frequency is 2.4 GHz and maximum radiation gain is 3.2dBi. The proposed antenna is useful for diversity antenna and smart antenna in modern wireless communication including MIMO (Multi-Input Multi-Output) and WLAN system. The sizes of the rectangular patch and the ground plane are $28mm{\times}28mm$ and $40mm{\times}50mm$, respectively. The simulation and experimental results show that the antenna radiation pattern can be changed with switch on/off configuration.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.3
• /
• pp.921-940
• /
• 2015

In this paper, we investigate the multi-resource allocation problem, a unique feature of which is that the multiple resources can compensate each other while achieving the desired system performance. In particular, power and time allocations are jointly optimized with the target of energy efficiency under the resource-limited constraints. Different from previous studies on the power-time tradeoff, we consider a multi-server case where the concurrent serving users are quantitatively restricted. Therefore user selection is investigated accompanying the resource allocation, making the power-time tradeoff occur not only between the users in the same server but also in different servers. The complex multivariate optimization problem can be modeled as a variant of 2-Dimension Bin Packing Problem (V2D-BPP), which is a joint non-linear and integer programming problem. Though we use state decomposition model to transform it into a convex optimization problem, the variables are still coupled. Therefore, we propose an Iterative Dual Optimization (IDO) algorithm to obtain its optimal solution. Simulations show that the joint multi-resource allocation algorithm outperforms two existing non-joint algorithms from the perspective of energy efficiency.

• 시스템엔지니어링워크숍
• /
• s.4
• /
• pp.70-80
• /
• 2004

Most rail system related simulations currently used are designed to simulate only one discipline system. This obviously assunes the other discipline system are running regularly not being affected by the system being simulated. In this paper a multi discipline simulator is proposed and its design concept is presented.A multi discipline simulator is the simultor in which major subsystems with different technical discipline are simulated simultaneously. The advantage of the simulator is in that it makes it possible to analyze the systems behavior while other discipline system vary. With this we can identify the possible to analyze the systems ehavior find their solutions. A proto type simulator has bee developed using object oriented programming. Object concept was judged best suitable to model the various multi-discipline self-controlling railway subsystems. It was applied to the target system, which is under development by the Korea Railroad Research institute. The test results show it is very useful in design verification. It could also be a good tool in research and development work to make to improe the system.

• Journal of Electrical Engineering and Technology
• /
• v.12 no.6
• /
• pp.2118-2126
• /
• 2017

The large-scale power system blackouts have indicated that conventional protection relays that based on local signals cannot fit for modern power grids with complicated setting or heavily loaded-flow transfer. In order to accurately detect various faulted lines and improve the fault-tolerance of wide-area protection, a novel multi-section weighed fault matching and detecting algorithm is proposed. The real protection vector (RPV) and expected section protection vectors (ESPVs) for five fault sections are constructed respectively. The function of multi-section weighed fault matching is established to calculate the section fault matching degrees between RPV and five ESPVs. Then the fault degree of protected line based on five section fault degrees can be obtained. Two fault detecting criterions are given to support the higher accuracy rate of detecting fault. With the enumerating method, the simulation tests illustrate the correctness and fault-tolerance of proposed algorithm. It can reach the target of 100% accuracy rate under 5 bits error of wide-area protections. The influence factors of fault-tolerance are analyzed, which include the choosing of wide-area protections, as well as the topological structures of power grid and fault threshold.

• Journal of KIISE:Information Networking
• /
• v.34 no.1
• /
• pp.27-32
• /
• 2007

Next-generation wireless networks are expected to support a wide range of services, including high-rate data applications, Various service types request differentiated QoSs(Qualities of Service) such as minimum data rate, accuracy, fairness and so on. Although resources of radio systems are limited, for many applications, it is important that certain QoS targets are required to be met. In this paper, we propose a QoS based scheduling algorithm for next generation systems, based on analyzing previous researches, and we develop the proposed QoS algorithm only for MIMO(multi-Input Multi-Output) systems. Moreover, we subsequently prove that the proposed algorithm optimize throughput relative to prespecified target values and converge to certain throughput.