• Journal of the Korean Geophysical Society
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• v.2 no.1
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• pp.75-88
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• 1999

A recent major subject of geophysical exploration is research into 3-D subsurface imaging with a composite information from the various geophysical data. In an attempt to interpret Schlumberger sounding data for the study area in 2-D and 3-D view, resistivity imaging was firstly performed and then pseudo-3-D resistivity volume was reconstructed by interpolating several 1-D resistivity plots. Electrical resistivity discontinuities such as fracture zone were successfully clarified in pseudo-3-D resistivity volume. The low resistivity zone mainly associated with fracture zone appears to develop down to granitic basement in the central part of the study area. Seismic velocity near the lineament is estimated to be approximately as small as 3,000 m/s, and weathering-layer for the southeastern part is interpreted to be deeper than for the northwestern part. Geophysical attributes such as electrical resistivity, seismic velocity, radioactivity for the Chojeong Area were analysed by utilizing a GIS software Arc/Info. The major fault boundaries and fracture zones were resolved through image enhancement of composite section (electrical resistivity and seismic refraction data) and were interpreted to develop in the southeastern part of the area, as characterized by low electrical resistivity and low seismic velocity. However, radioactivity attribute was found to be less sensitive to geological discontinuities, compared to resistivity and seismic velocity attributes.

• Journal of the Korean Vacuum Society
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• v.18 no.1
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• pp.9-14
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• 2009

We calculated tetragonal-$HfO_2$/Si superstructures using density functional theory. When a and b-axes of cubic-$HfO_2$ were increased to be matched with those of Si for epitaxy contact, c-axis was decreased by 2%. Eight models of interface layers were produced by choosing different terminating layers of tetragonal-$HfO_2$ and Si substrate at the interface. It was found that tetragonal-$HfO_2$ $(004)_{1/4}$/Si $(004)_{3/4}$ superstructure was the most favorable and tetragonal-$HfO_2$ (004)$_{1/4}$/Si (002) superstructure was the most unfavorable. In tetragonal-$HfO_2$ $(004)_{1/4}$/Si (002) superstructure, there were two oxygen vacancies in tetragonal-$HfO_2$ as two oxygen atoms were moved to Si substrate located at the interface.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.7
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• pp.744-751
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• 2010

In this paper, the design of multilayer radome within, the insertion loss, －0.3 dB in X-band with PSO was carried out based on two cases. The first is that, deciding material constant of skin and core, each layer thickness of c-sandwich radome with PSO is found and the second is that, deciding material constant and thickness of the skins of both sides, the material constant and thickness of three layers between skins of both sides using PSO is decided. The performance of the designed radome almost agreed with the required performance. It was showed that the radome design applying PSO algorithm is easy and fast and the optimum radome is also designed in combination of the various parameters of radome. From these results, the radome having various performance can be designed except the tedious calculation and also be applied to various radome structure.

• The KIPS Transactions:PartC
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• v.13C no.7 s.110
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• pp.803-812
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• 2006

This paper analytically evaluates the FEC(Forward Error Correction) symbol size's effect on the performance and energy consumption of 802.11 protocol with the block FEC algorithm over WSN(Wireless Sensor Network). Since the basic recovery unit of block FEC algorithms is symbols not bits, the FEC symbol size affects the packet correction rate even with the same amount of FEC check bits over a given WSN channel. Precisely, when the same amount of FEC check bits are allocated, the small-size symbols are effective over channels with frequent short bursts of propagation errors while the large ones are good at remedying the long rare bursts. To estimate the effect of the FEC symbol site, the paper at first models the WSN channel with Gilbert model based on real packet traces collected over TIP50CM sensor nodes and measures the energy consumed for encoding and decoding the RS (Reed-Solomon) code with various symbol sizes. Based on the WSN channel model and each RS code's energy expenditure, it analytically calculates the transmission efficiency and power consumption of 802.11 equipped with RS code. The computational analysis combined with real experimental data shows that the RS symbol size makes a difference of up to 4.2% in the transmission efficiency and 35% in energy consumption even with the same amount of FEC check bits.

• Journal of Conservation Science
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• v.28 no.4
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• pp.403-410
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• 2012

The brine treatment applied during the fabrication of forged high tin bronze objects is considered effective at the removal of surface oxide layers developed at elevated temperatures. There is not much information, however, available for the understanding of its exact effect and purpose. This work performed laboratory experiments to characterize the effect brine treatments produce on the surface of bronze objects during fabrication. Specimens were first made in the bronze shop of the Yongin folk village under varying conditions of brine treatments, and the results obtained were then used in the following laboratory experiments where the effect of brine treatments were investigated in terms of brine concentrations, alloy compositions and thermo-mechanical treatments. The results show that oxide layers generated at high temperature are easily removed by the brine treatment. It was found that the element, chlorine, played a key role in the removal of such oxide layers as opposed to the other constituent of the brine, sodium, makes no notable contribution. In bronze alloys containing 22% tin, this brine effect is obtained regardless of the application of forging as long as the brine concentration is over 0.5% based on weight. In alloys containing lead, however, no brine effect is observed due to the molten lead that emerges from inside the hot bronze specimen and forms a thin layer on its surface.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.223-228
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• 2008

Recently, various types of wireless access networks, such as WLAN, WiBro and HSDPA, etc, have been successfully deployed by commercial service providers (i.e., KT, KTF). In this situation, there are many efforts to provide high quality of services to guarantee seamless mobility between heterogeneous networks. The IP layer mobility protocols are efficient mechanisms to provide seamless mobility between IP based heterogeneous networks as well as homogeneous networks. However, to apply IP mobility protocols in real heterogeneous networks (i.e., WiBro and HSDPA), we must consider not only the basic features of techniques of wireless access networks (i.e., Data rate, Coverage, Quality of Service) but also the problem of real environment of service provider (i.e., Expanse cost to change the access network). Due to this reason, it is difficult to satisfy required conditions by using only one IP mobility protocol in real heterogeneous networks. Therefore, in this paper, we propose an efficient mobility protocol to solve the complex problems that are occurred in real heterogeneous networks. The proposed protocol, so-called, "Hybrid Mobile IP" tries to provide a synergy effect by integrating Client Mobile IPv4 (CMIPv4) and Proxy Mobile IPv4 (PMIPv4), and using the two mobility protocols selectively according to the situation of real heterogeneous networks.

• Archives of Plastic Surgery
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• v.37 no.4
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• pp.385-390
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• 2010

Purpose: The purpose of this study is to demonstrate the usefulness of the high resolutional ultrasonographic features in patients with foreign body. Methods: From September 2007 to August 2009, we retrospectively reviewed high resolutional ultrasonogram using 5~12 MHz linear transducer of 13 patients presenting with inflammation after foreign body injection. They were referred for complications after foreign body injection. Injected foreign bodies were 4 silicone, 4 paraffin, 2 artecoll, and 3 unknown. We treated them with foreign body removal (7), foreign body removal and corrective plastic surgery (4), and conservative treatment with antibiotics and steroid injection (2). Results: High resolutional ultrasonography well demonstrated the existence of foreign body and it's overall size, location within the tissue layer, and vascularity. Comparison between preoperative and postoperative ultrasonographic findings was useful not only to evaluate the prognosis but also to plan the treatment. These ultrasonographic findings aided in precise assessment of the contour and location of the foreign body and led to an accurate surgery. We were able to acquire various information in order to set a detailed plan for the operation which in turn, led to a precise, successful surgery. After the treatment, complication did not occur in 12 patients, except 1 patient. But this patient was also treated after reoperation. Postoperative high resolutional ultrasonography shows almost foreign body removed and inflammation disappeared. Conclusion: Considering the usefulness of highresolution ultrasonography in foreign body injection, highresolution ultrasonography would be necessary for both the patient and the doctor. Preoperative and postoperative high resolutional ultrasonography is highly accurate, safe, inexpensive and easy. It can be a useful modality in foreign body after plastic surgery.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.2
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• pp.189-196
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• 2005

Recently as map making skills developed and as digital maps prevailed, peoples began to take interest in the realistic 3dimension topography rather than the flat 2 dimension one. The experiment is done by using the topographical information from the digital maps, To analyze the preciseness of this 3dimension topography, analysis of the coordinate-changed standard map image and the location errors of the plane and height from digital values of the map's topography by layers and features, were done. The visual results of locational values differed by every programs of coordinate transformation. Errors of locations also appeared from the methods of correcting the visual sources, when deciding the standard source's datum point. The plan's accuracy of the image data coordinate transformation is about ${\pm}4.1m$. In ground distance, therefore, it is included in the allowed error of the 1:25,000 scale changed map, satisfying the plan's accuracy. Also, by the use of reasonably spaced grid, it satisfied the visual topographical accuracy. Because the 3 dimension topographical map can be produced effectively and rapidly by using various scale's standard map image and the digital map, the further practical use of 3 dimension topographic map made by using the existing topographies and changed maps has high expectations.

• Journal of KIISE:Software and Applications
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• v.30 no.11
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• pp.1025-1036
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• 2003

In industry, it is a current trend that systems are developed by using Enterprise JavaBeans(EJB) technology for reducing the cost and the time. Thus, the architecture of EJB is getting more essential to enhance reusability, extensibility and portability of system. However little has been studied in the realm of the practical software architectures for EJB. The architecture has just bean studied in abstract level, but not in concrete level providing the method to substantiate it using the practical J2EE techniques. Just using the EJB technology doesn't guarantee the reusability of the artifacts because EJB specification provides the characteristics and architecture for only fine grained components as session and entity bean. In this paper, we propose the enterprise software architecture for the systems based on EJB and the concrete techniques for implementing that. Also, design patterns of modeling efficient enterprise architecture are represented. By analyzing both the strengths and the weaknesses of suggested design patterns, EJB design patterns which are suitable for each layer of enterprise architecture will be identified. Through the component which design patterns are applied, the architecture can support the optimized relationship between the components. Five techniques for designing components from fine grained to coarse grained based on EJB technology, and architecture design techniques including transaction and assembling techniques are proposed.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.2
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• pp.94-101
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• 2008

Non-volatile RAM (NVRAM) is a form of next-generation memory that has both characteristics of nonvolatility and byte addressability each of which can be found in nonvolatile storage and RAM, respectively. The advent of NVRAM may possibly bring about drastic changes to the system software landscape. When NVRAM is efficiently exploited in the system software layer, we expect that the system performance can be significantly improved. In this regards, we attempt to develop a new Flash file system, named MiNVFS (Metadata in NVram File System). MiNVFS maintains all the metadata in NVRAM, while storing all file data in Flash memory. In this paper, we present quantitative experimental results that show how much performance gains can be possible by exploiting NVRAM. Compared to YAFFS, a typical Flash file system, we show that MiNVFS requires only minimal time for mounting. MiNVFS outperforms YAFFS by an average of around 400% in terms of the total execution time for the realistic workloads that we considered.