• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.5
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• pp.609-621
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• 1998

Sand ridges in the South Sea of Korea have been investigated to reveal the surface morphology and vortical variation in sediment physical property. Both field and laboratory methods such as high resolution subbottom profiling, side scan sonar, and physical property and sediment textural study on cored sediments were employed. Asymmetric sand waves are found on the ridge, No prominent difference in the sediment was recorded throughout the ridge area. Sediment sorting is generally poor due to interbedded mud. Average compressional wave velocity is 1753 m/sec for the sand dominated core section, Most of cores show two prominent facies: facies A and B. Facies A is defined as modern mud sediment and B is dominated by relict sand. Facies B is characterized by gravel, sand, and shell fragment, It is suggested that the facies B was developed in transgressive environment by tide and sporadic high energy events.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.1
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• pp.51.1-51.1
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• 2013

We present molecular line observations of a small group of Young Stellar Objects (YSOs), L1251C. Observations by Spitzer Space Telescope legacy program "From Molecular Cores to Planet Forming Disks"(c2d; Evans et al. 2003) revealed that there are three YSOs within ~15" in L1251C: IRS1 (Class I), IRS2 (Class II), and IRS3 (Class II). In order to understand the molecular environment around these YSOs, we carried out the KVN single-dish observations in $HCO^+$ J=1-0, $H^{13}CO^+$ J=1-0, $N_2H^+$ J=1-0 and HCN J=1-0. CO J=1-0 was also mapped in L1251C with the TRAO 14m telescope. Integrated intensity maps of high density tracers such as $H^{13}CO^+$ J=1-0, $N_2H^+$ J=1-0 and HCN J=1-0 show similar emission distributions, whose peaks are off from the positions of YSOs. However, $HCO^+$ J=1-0, which is believed to trace both infall and outflow, presents its emission distribution different from those of other molecular transitions. The line profile of $HCO^+$ J=1-0 is superimposed by two velocity (narrow and broad) components. The $HCO^+$ outflow map reveals multiple structures while the CO outflow map elongates mainly along the EW direction. With the KVN single dish, the 22 GHz $H_2O$ maser emission has been also monitored toward L1251C to find variations of the systemic velocity and intensity with time.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.6
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• pp.703-709
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• 2014

In the AMP(Asymmetric Multiprocessing) based dual core using core-specific operating system in a single processor system, shared memory method is used to send data between processors in dual core. To used shared memory in different operating systems, there is a problem of needing to solving the issue of message communication and synchronization between the two operations systems. In this paper, separate memory controller was used for data sharing between different processor cores in dual core environment. This controller can designate two slave ports to allow simultaneous access from two processors, and in the case of process data simultaneously by two processors, priority order of slave ports is determined through memory mediator. When sending data from A to B processor, SRAM area was logically separated into 8 pages. It allowed using memory area from multiple processes with the size of 4KByte per page, and control register with the size of 4Byte was used to discern the usability of current page.

• Journal of Technologic Dentistry
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• v.39 no.1
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• pp.43-52
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• 2017

Purpose: Physical and chemical properties of gold is most suitable to be restored of teeth to its original state. Recently zirconia was used instead of gold because of esthetical and intimacy of human body. Because of high strength and high abrasion resistance of zirconia, all zirconia artificial tooth lead to wear the original tooth of opposite site. To preserve this original tooth, zirconia artificial tooth covered with dental ceramic glass was used. When joining the zirconia core and dental ceramic glass, difference of their thermal expansion coefficient and wetting ability is generated the residual stress at interface lead to crack. In order to solve this problem, intermediate layer what is called zir-liner was imported to decrease the residual stress and increase the bonding strength. Methods: In this study, to identify the optimum conditions for manufacturing process, various methods to rough the surface of zirconia core were adopted, and vary the thickness of interlayer, and analyzed bond strength. Results: Bond strength of sanding specimens group showed higher than that of non-sanding specimens group, and once applied intermediate layer with sanding specimens showed highest bond strength with 28 MPa. SEM photomicrographs of zirconia cores fired at $1500^{\circ}C$ showed parallel straight lines in sanding and pockmarked surface in blasting surfaces as abrasion traces. Observation of the destruction section after shear test by SEM were carried out. Liner applied non-sanding group and non-liner applied sanding group all showed interfacial crack. Sandblasting group with non-liner showed remained dental ceramic glass on the surface of zirconia. Sandblasting group with once applied liner showed partially remained liner and dental ceramic glass on the surface of zirconia. XRD analysis revealed that sandblasting group showed higher monoclinic peaks than other specimens group and this result was due to the high collision energy for stress induced phase transformation. Conclusions: A study on the improvement of bonding strength between zirconia and dental ceramic glass steadily carried out for the future to practical use.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.33.1-33.1
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• 2016

Dwarf elliptical galaxies (dEs), the most abundant galaxy type in clusters, were recently shown to exhibit a wide variety in their properties. Particularly, the presence of blue cores in some dEs, what we call dE(bc), supports the scenario of late-type galaxy infall and subsequent transformation into red, quiescent dEs. While several transformation mechanisms for these dE(bc)s within cluster environment have been proposed, all these processes are able to explain only some of the observational properties of dEs. In this context, internal kinematic properties of dE(bc)s provide the most crucial evidence to discriminate different processes for the formation of these galaxies. We present Gemini Multi Object Spectrograph (GMOS) long-slit spectroscopy of two dE(bc)s in the Virgo cluster. We obtained radial profiles of velocity and velocity dispersion out to ~1.3 effective radius. We found that two dE(bc)s exhibit kinematically decoupled components as well as distinct peculiar features in velocity profiles, supporting the scenario of mergers. We also found that these galaxies are structurally compatible with low surface brightness component of blue compact dwarf galaxies. We suggest that a part of dE(bc)s in the Virgo Cluster were formed through galaxy merger in low density environment such as galaxy group or outskirt of the cluster, and then were quenched by subsequent effects within cluster environment.

• Journal of the Korean Geographical Society
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• v.48 no.6
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• pp.967-977
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• 2013

This study aims to analyze the core contents of classical geomancy, and compromising the contemporary interpretation. Also it empahsizes the scientific aspects of reinterpretation. The cores are 'JiGi' and 'Balbok'(Positive change in fortune), followed by subjective methodology, which give a provision about right Pungsu place. Although there are weaknesses in terms of geomancy, scholars searching for classical geomancy have scientific ideas including traditional ecology and adative strategy. Traditional ecology with supported natural science becomes ecological science, and the adaptive strategy is to search for more physiologically comfortable place. These two reinterpretations give new perspective and subjects which lead to traditional view of nature or symbolic system. The subjects could have relationships with health or living a long life or heal.

• Korean Chemical Engineering Research
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• v.45 no.6
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• pp.611-618
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• 2007

We demonstrate the sol-gel coating technique of colloidal clusters for producing hollow micro-particles with complex morphologies. Cross-linked amidine polystyrene (PS) microspheres were synthesized by emulsifier-free emulsion copolymerization of styrene and divinylbenzene. The amidine PS particles were self-organized inside toluene-in-water emulsion droplets to produce large quantities of colloidally stable clusters. These clusters were coated with thin silica shell by sol-gel reaction of tetraethylorthosilicate (TEOS) and ammonia, and the organic polystyrene cores were removed by calcination at high temperature to generate nonspherical hollow micro-particles with complex morphologies. This process can be used to prepare hollow particles with shapes such as doublets, tetrahedra, icosahedra, and others.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.6A
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• pp.640-647
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• 2006

This paper describes a design of AES-based CCMP(Counter mode with CBC-MAC Protocol) core for IEEE 802.11i wireless LAN security. To maximize the performance of CCMP core, two AES cores are used, one is the counter mode for data confidentiality and the other is the CBC node for authentication and data integrity. The S-box that requires the largest hardware in ARS core is implemented using composite field arithmetic, and the gate count is reduced by about 27% compared with conventional LUT(Lookup Table)-based design. The CCMP core was verified using Excalibur SoC kit, and a MPW chip is fabricated using a 0.35-um CMOS standard cell technology. The test results show that all the function of the fabricated chip works correctly. The CCMP processor has 17,000 gates, and the estimated throughput is about 353-Mbps at 116-MHz@3.3V, satisfying 54-Mbps data rate of the IEEE 802.11a and 802.11g specifications.

• The KIPS Transactions:PartA
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• v.18A no.1
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• pp.19-24
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• 2011

As era of multi-core processors has arrived, transactional memory has been considered as an effective method to achieve easy and fast multi-threaded programming. Various hardware transactional memory systems such as UTM, VTM, FastTM, LogTM, and LogTM-SE, have been introduced in order to implement high-performance multi-core processors. Especially, LogTM-SE has provided study performance with an efficient memory management policy and a practical thread scheduling method through conflict detection based on signatures. However, increasing number of cores on a processor imposes the hardware complexity for signature processing. This causes overall performance degradation due to the heavy workload on signature comparison. In this paper, we propose a new architecture of multiple signature comparison to improve conflict detection of signature based transactional memory systems.

• The Journal of the Acoustical Society of Korea
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• v.26 no.2E
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• pp.44-49
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• 2007

Donghae City - Ulleung Island Line (DC-UI Line) is a representative line for underwater and geoacoustic modeling in the middle western East Sea. In this line, an integrated model of P-wave velocity is proposed for a low-frequency range target (<200 Hz), based on high-resolution seismic profiles (2 - 7 kHz sonar and air-gun), shallow and deep cores (grab, piston, and Portable Remote Operated Drilling), and outcrop geology (Tertiary rocks and the basement on land). The basement comprises 3 geoacoustic layers of P-wave velocity ranging from 3750 to 5550 m/s. The overlying sediments consist of 7 layers of P-wave velocities ranging from 1500 to 1900 m/s. The bottom model shows that the structure is very irregular and the velocity is also variable with both vertical and lateral extension. In this area, seabed and underwater acousticians should consider that low-frequency acoustic modeling is very range-dependent and a detailed geoacoustic model is necessary for better modeling of acoustic propagation such as long-range surveillance of submarines and monitoring of currents.