• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.6
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• pp.68-73
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• 2008

In this paper, we propose watermark algorithm called TDWA(Time-Division Watermarking Algorithm) and we applied the proposed algorithm to H.264 video coding standard. We establish that a proposed algorithm is applied to H.264 baseline profile CODEC. The proposed algorithm inserts a watermark into the spatial domain of several frames. We can easily insert strong and invisible watermarks into original pictures using this method. For verification of the proposed algorithm we design hardware core using Verilog-HDL and Excalibur for JM 8.7 code with hardware & software co-simulation. As a result of verification, the PSNR between watermarked pictures and original pictures are more than 60dB and we found the watermark is kept more than 80% after encoding of H.264/AVC with quantization parameter of 28 in baseline profile.

• Journal of Mechanical Science and Technology
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• v.18 no.1
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• pp.74-81
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• 2004

The KSNP Steam Generators (Youngkwang Unit 3 and 4, Ulchin Unit 3 and 4) have a problem of U-tube fretting wear due to Flow Induced Vibration (FIV). In particular, the wear is localized and concentrated in a small area of upper part of U-bend in the Central Cavity region. The region has some conditions susceptible to the FIV, which are high flow velocity, high void fraction, and long unsupported span. Even though the FIV could be occurred by many mechanisms, the main mechanism would be fluid-elastic instability, or turbulent excitation. To remedy the problem, Eggcrate Flow Distribution Plate (EFDP) was installed in the Central Cavity region or Ulchin Unit 5 and 6 steam generators, so that it reduces the flow velocity in the region to a certain level. However, the cause of the FIV and the effectiveness of the EFDP was not thoroughly studied and checked. In this study, therefore the Stability Ratio (SR), which is the ratio of the actual velocity to the critical velocity, was compared between the value before the installation of EFDP and that after. Also the possibility of fluid-elastic instability of KSNP steam generator and the effectiveness of EFDP were checked based on the ATHOS3 code calculation and the Pettigrew's experimental results. The calculated results were plotted in a fluid-elastic instability criteria-diagram (Pettigrew, 1998, Fig. 9). The plotted result showed that KSNP steam generator with EFDP had the margin of Fluid-Elastic Instability by almost 25％.

• Journal of Advanced Navigation Technology
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• v.14 no.2
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• pp.151-160
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• 2010

For the realization of future intelligent transportation systems, fine-grained lane-by-lane traffic monitoring and control functionalities are among the most important technology barriers to overcome. To satisfy the accuracy requirement for traffic monitoring, a GNSS receiver network is designed. The designed receiver network consists of three different types of entities; reference server, broadcaster, and client. For deployment flexibility, all the entities utilize the international message standard RTCM SC-104 version 3.0. For fine-grained traffic monitoring, the client is designed to utilize position-domain carrier-smoothed-code filters to provide accurate vehicle coordinates in spite of frequent addages and outages of visible satellites. An experiment result is presented to evaluate the positioning accuracy of the proposed method.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.10
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• pp.1002-1010
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• 2015

Natural gas hydrates are newly emerging as an environment-friendly source of energy to substitute for fossil fuels in the 21stcentury.NGHs are reported to holds much amounts of natural gas (up to 182 standard volumes of gas per volume of hydrate); they are easy to store and safe to carry at about minus 20 degree Celsius under atmospheric pressure because of the self-preservation phenomenon of gas hydrates. The transporting method by gas-ice-hydrate ship carriers has been introduced and developed by a variety of industry and research institutions. Our team has been conducted to develop NGH total systems, including a breakthrough NGH carrier for sea transportation, since 2011. The NGH pellet carrier does not require a separate cooling system for cargo, and the initial temperature is maintained through insulation of the cargo tanks throughout the transport to the final destination. The heat conducted from the exterior and passing through the insulation material of the hull should be cut off as much as possible, but heat inflow inside the cargo tank from an external source is inevitable during transport. In this study, the heat transfer in a cargo tank of a 115K NGH carrier was analyzed through simulation with a commercial CFD code to estimate the boil-off gas/boil-off rate on the developed carrier and understand major hazards that could significantly impact the safety of the vessel.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.213-220
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• 2006

Plant construction industry is a high value-adding industry because it is complex industry comprising engineering, procurements of equipments and construction. So, Revenue increase in overseas plant projects would boost up not only domestic construction industry but also growth of national economy. Recently, overseas plant-construction market is expanding dramatically. For instant, Middle-east countries are constantly increasing their orders for the construction of petro-chemical plants stimulated by sky-rocketing oil prices. The purpose of this research is to develop management techniques for plant projects such as work break-down structure, knowledge management system, logistics & procurement system, and risk assessment tools. We believe our research would contribute to the competion of Korean engineeing companies and contractors in overseas plant-construction market.

• Journal of Korean Society of Steel Construction
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• v.16 no.5 s.72
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• pp.661-669
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• 2004

In the steel structure of high-rise buildings, a connection analysisand a column design have been made after welding and bolting suitable gaps. Each country, however, has different codes, and such differences are very big. American steel has been designed according to a code that all axial loads can be carried from the upper parts to the lower parts as determined by the designer, but Korean and Japanese steel have been designed by 1/4 of the standard of all axial loads. In this paper, a metal touch experiment was done as an intermediation parameter with a connecting location and a connecting method for economic and constructive efficiency. Every specimen is tested by a low-to-high displacement control to grasp ultimate strength, displacement, the connection's lateral deflection, and stress. The results of the test were compared and analyzed.

• Journal of Acupuncture Research
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• v.37 no.1
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• pp.13-18
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• 2020

This review examined recently published (July 2014 to June 2017), randomized controlled trials (RCTs) which investigated the safety and effectiveness of combined Korean medicine/complementary alternative medicine (CAM) and Western medicine, to indicate the direction for integrative medical practice. The Korean Medicine Convergence Research Information Center evidence-based medicine database (KMCRIC EBM DB) was used to retrieve relevant RCTs indexed in the last 3 years. Study design, country, sample size, disease/condition with the Korean Standard Classification of Diseases code, interventions, direction of outcomes, and adverse events were extracted and summarized. A total of 93 RCTs were included in this review. Acupuncture/moxibustion was the most commonly used intervention (n = 47; 51%), and 19% (n = 18) of the studies treated musculoskeletal disorders, followed by circulatory disorders (n = 16; 17%), and mental and behavioral disorders (n = 9; 10%). Integrative treatment was reported as more effective than monotherapy in approximately 83% of these studies. Adverse events were poorly reported in most studies. This review suggests that integrative treatments are feasible, effective, and safe for various diseases/conditions, based on the evidence from recently published RCTs. Future studies on integrative healthcare are warranted.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.5
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• pp.335-344
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• 2003

The image compression based on discrete wavelet transform has been widely accepted in industry since it shows no block artifacts and provides a better image quality when compressed to low bits per pixel, compared to the traditional JPEG. The coefficients generated by discrete wavelet transform are quantized to reduce the number of code bits to represent them. After quantization, lossless coding processes are usually applied to make further reduction. This paper presents a new and efficient lossless coding algorithm for quantified wavelet coefficients based on the statistical properties of the coefficients. Combined with discrete wavelet transform and quantization processes, our algorithm has been implemented as an image compression chip, using 0.5${\mu}{\textrm}{m}$ standard cells. The experimental results show the efficiency and performance of the resulting chip.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.6
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• pp.600-613
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• 1997

The implementation of a BTS(Base station Transceiver) for WLL system using W-CDMA(Wideband-Code Division Multiple Access) method is presented in this paper. It consists of three boards; receiver, transmitter and RF controller. Some RF parameters are considered and simulated by the RF simulation S/W using commercial and customized components specifications. The implemented transceiver of 5 MHz RF channel bandwidth satisfies the system requirements of a transceiver such as dynamic range, sensitivity in the receiver and spurious emission suppression in the transmitter. At the receiver, the experimental measurement showed 2.86 dB of NF and 60 dB above of dynamic range in AGC(Automatic Gain Control) locking. At the transmitter, the -49.46 dBc of spurious emission suppression is attained when the output power of the transmitter is 34.3 dBm. These results are good enough to meet to standard performance specifications.

• Industrial Engineering and Management Systems
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• v.9 no.3
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• pp.285-293
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• 2010

To obtain visible and traceable information from the supply chain, HW/SW standards for the EPC global network, which process electronic product code (EPC) data read from Radio frequency identification (RFID) tags, are regarded as the de facto industry standard. Supply chain participants install information service systems and provide logistics information to partners by following the EPCglobal architecture framework. Although quality of service (QoS) is essential for providing dependable and scalable services as pointed out by Auto-ID Lab, only a few models for the performance analysis of QoS-related work have been developed in the context of EPC information service systems. Specifically, doing so allows alternative design choices to be tested in an easy and cost-effective manner and can highlight potential performance problems in designs long before any construction costs are incurred. Thus, in this study we construct a model of an EPC information service system for the purposes of performance analysis and designing a dependable system. We also develop a set of building blocks for analytical performance models. To illustrate how the model works, we determine the characteristics of an EPC information service system and then select a combination of these proven modeling concepts. We construct a performance model that considers the response time and shows how to derive meaningful performance values. Finally, we compare the analytical results to measurements of the EPC information service system.