• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.1
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• pp.49-62
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• 2024

Reckless development of the underground by rapid urbanization causes inspection delay on replacement of existing structure and installation new facilities. However, frequent accidents occur due to deviation in construction design planned by inaccurate location information of underground structure. Meanwhile, the electrical resistivity survey, knowns as non-destructive method, is based on the difference in the electric potential of electrodes to measure the electrical resistance of ground. This method is significantly advanced with multi-electrode and deep learning for analyzing strata. However, there is no study to quantitatively assess change in electrical resistance according to geometric conditions of structures. This study evaluates changes in electrical resistance through geometric parameters of electrodes and structure. Firstly, electrical resistance numerical module is developed using generalized mesh occurring minimal errors between theoretical and numerical resistance values. Then, changes in resistances are quantitatively compared on geometric parameters including burial depth, diameter of structure, and distance electrode and structure under steady current condition. The results show that higher electrical resistance is measured for shallow depth, larger size, and proximity to the electrode. Additionally, electric potential and current density distributions are analyzed to discuss the measured electrical resistance around the terminal electrode and structure.

• Journal of Advanced Navigation Technology
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• v.9 no.1
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• pp.48-55
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• 2005

In this paper, we propose an efficient moving object tracking technique for multi-camera surveillance system. Color CCD cameras used in this system are network cameras with their own IP addresses. Input image is transmitted to the media server through wireless connection among server, bridge, and Access Point (AP). The tracking system sends the received images through the network to the tracking module, and it tracks moving objects in real-time using color matching method. We compose two sets of cameras, and when the object is out of field of view (FOV), we accomplish hand-over to be able to continue tracking the object. When hand-over is performed, we use MHI(Motion History Information) based on color information and M-bin histogram for an exact tracking. By utilizing MHI, we can calculate direction and velocity of the object, and those information helps to predict next location of the object. Therefore, we obtain a better result in speed and stability than using template matching based on only M-bin histogram, and we verified this result by an experiment.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.4
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• pp.409-417
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• 2013

Mu-communication board supported by multi-communication is designed with Atxmega 128A1 which is a low power energy consuming of 8-bit microcontroller. ATxmega128A1 microcontroller consists of 8 UART(Universal asynchronous receiver/transmitter) ports which can be setting appropriate user interface having command line interpreter(CLI) program with each port, 2 kbytes EEPROM, 128 kbytes flash memory, 8 kbytes SRAM. 8 URAT ports are used for the multi communication modem, GPS module, etc. and EEPROM is used for saving a configuration for program running, and flash memory of 128 kbytes is used for storing a Firm Ware, and 8 kbytes SRAM is used for stack, storing memory of global variables while program running. If we uses the hybrid communication of path optimization of VHF, TRS and CDMA to remote control AtoN(aid to navigation), it is able to remove the communication shadow area. Even though there is a shadow area for individual communication method, we can select an optimum communication method. The compatibility of data has been enhanced as using of same data frame per communication devices. For the test, 8640 of data has been collected from the each buoy during 30 days in every 5 minutes and the receiving rate of the data has shown more than 99.4 %.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.310-315
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• 2017

Automotive waterproof connectors are highly functional parts that must be air-tight in a complex environment. In the LSR multi-cavity injection molding process for manufacturing waterproof connectors, it is important to maintain a uniform curing temperature between the cavities in order to obtain a quality product. For this purpose, we designed the capacity of the cartridge heater differently for each position, and then linked the heat transfer analysis and optimization module to obtain the optimal cartridge heater capacity. As a result of the optimization analysis, the temperature deviation between cavities was decreased from $13.1^{\circ}C$ to $8.1^{\circ}C$ compared with the case in which constant heater capacity was applied, so that the design criterion could be satisfied within a temperature deviation of $10^{\circ}C$ for uniform curing. This study suggests that this method can be applied efficiently to the design of a large area multi-cavity LSR mold heater.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.5
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• pp.485-495
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• 2000

The parallel computer system that uses parallel program on the application such as a large scale business or complex operation is required. One of crucial operation of parallel computer system is synchronization. A representative method of synchronization is barrier synchronization. A barrier forces all process to wait until all the process reach the barrier and then releases all of the processes. There are software schemes, hardware scheme, or combinations of these mechanism to achieve barrier synchronization which tends to use hardware scheme. Besides, barrier synchronization lets parallel computer system fast because it has fewer start-up overhead. In this paper, we propose a new switch module that can implement fast and fault-tolerant barrier synchronization in hardware scheme. A proposed barrier synchronization is operated not in full-switch-driven method but in processor-driven method. An effective barrier synchronization is executed with inexpensive hardware supports. Therefore, a new proposed hardware barrier synchronization is designed that it is operated in arbitrary network topology. In this paper, we only show comparison of barrier synchronization on Multistage Interconnection Network. This research results in 24.6-24.8% reduced average delay. Through this result, we can expect lower average delay in irregular network.

• Journal of the Korean Society of Radiology
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• v.8 no.7
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• pp.371-376
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• 2014

The process of flip-chip bump bonding, Au wire bonding and encapsulation were sucessfully developed and modularized. The CdTe sensor and ROIC were optimally jointed together at $150^{\circ}C$ and $270^{\circ}C$ respectively under24.5 N for 30s. To make SnAg bump on ROIC easy to be bonded, the higher bonding temperature was established than CdTe sensor's. In addition, the bonding pressure was lowered minimally because CdTe Sensor is easier to break than Si Sensor. CdTe multi-energy sensor module observed were no electrical failures in the joints using developed flip chip bump bonding and Au wire bonding process. As a result of measurement, shearing force was $2.45kgf/mm^2$ and, it is enough bonding force against threshold force, $2kgf/mm^2s$.

• Journal of the Microelectronics and Packaging Society
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• v.6 no.2
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• pp.37-43
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• 1999

Modules of the system that requires large capacity and high-speed information processing are implemented in the form of MCM that allows high-speed data processing, high density circuit integration and widely applied to such fields as ATM, GPS and PCS. Hence we developed the ATM switching module that is consisted of three chips and 2.48 Gbps data throughput, in the form of 10 multi-layer by Cu/Photo-BCB and 491pin PBGA which size is $48 \times 48 \textrm {mm}^2$. hnologies required for the development of the MCM includes extracting parameters for designing the substrate/package through the interconnect characterization to implement the high-speed characteristics, thermal management at the high-density MCM, and the generation of the testability that is one of the most difficult issues for developing the MCM. For the development of the ATM Switching MCM, we extracted signaling delay, via characteristics and crosstalk parameters through the interconnect characterization on the MCM-D. For the thermal management of 15.6 Watt under the high-density structure, we carried out the thermal analysis. formed 1.108 thermal vias through the substrate, and performed heat-proofing processing for the entire package so that it can keep the temperature less than $85^{\circ}C$. Lastly, in order to ensure the testability, we verified the substrate through fine pitch probing and applied the Boundary Scan Test (BST) for verifying the complex packaging/assembling processes, through which we developed an efficient and cost-effective product.

• The Journal of the Korea Contents Association
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• v.22 no.3
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• pp.500-512
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• 2022

Post-Occupancy Evaluation (POE), which is one of the construction environment evaluation methods, is a series of processes that ask about the functional requirements and satisfaction of an object from a life cycle perspective such as design/construction/residence. However, there are no POE research activities targeting large-scale units. On the other hand, large-scale third-phase new towns are being developed. Therefore, this study conducted a post-residence evaluation (POE) research activity in a large-scale unit (Multifunctional Administrative City). The procedure of this study is to conduct a literature survey on the current status and implications of the multi-functional administrative city area, and based on the research data, derive the Happy City evaluation index for the major issues and special issues of the Happy City. Afterwards, 450 questionnaires were conducted for the residents of Happy City, and POE analysis was performed on the derived data for each module. And based on the analysis results, implications such as problems and improvement points for the current status of the Happy City were derived. This can be used as a basis for the expansion of a large-scale new city into a self-sufficient city, and it can be used as a basic data for the development and improvement of a happy city that meets social needs in the future.

• Journal of Advanced Navigation Technology
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• v.27 no.2
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• pp.190-196
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• 2023

Recently, following the development of LIDAR technology which can detect distance from the object, the interest for LIDAR based 3D object detection network is getting higher. Previous networks generate inaccurate localization results due to spatial information loss during voxelization and downsampling. In this study, we propose an attention-based convergence method and a camera-LIDAR convergence system to acquire high-level features and high positional accuracy. First, by introducing the attention method into the Voxel-RCNN structure, which is a grid-based 3D object detection network, the multi-scale sparse 3D convolution feature is effectively fused to improve the performance of 3D object detection. Additionally, we propose the late-fusion mechanism for fusing outcomes in 3D object detection network and 2D object detection network to delete false positive. Comparative experiments with existing algorithms are performed using the KITTI data set, which is widely used in the field of autonomous driving. The proposed method showed performance improvement in both 2D object detection on BEV and 3D object detection. In particular, the precision was improved by about 0.54% for the car moderate class compared to Voxel-RCNN.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.4B
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• pp.771-782
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• 2000

In this paper, an H.263 video codec is implemented by adopting the concept of hardware and software co-design. Each module of the codec is investigated to find which approach between hardware and software is better to achieve real-time processing speed as well as flexibility. The hardware portion includes motion-related engines, such as motion estimation and compensation, and a memory control part. The remaining portion of theH.263 video codec is implemented in software using a RISC processor. This paper also introduces efficient design methods for hardware and software modules. In hardware, an area-efficient architecture for the motion estimator of a multi-resolution block matching algorithm using multiple candidates and spatial correlation in motion vector fields (MRMCS), is suggested to reduce the chip size. Software optimization techniques are also explored by using the statistics of transformed coefficients and the minimum sum of absolute difference (SAD)obtained from the motion estimator.