• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.1B
• /
• pp.1-10
• /
• 2007

We propose a new approach to accommodate bidirectional asymmetric traffic demands as well as unexpected dynamic internet traffic variation in the WDM mesh network by using optical networking technologies. In the proposed scheme, an intermediate node determines the optical path based on the switching statistics of IP router of the node which characterizes the Internet traffic variation, which in effect provides a dynamic and distributed traffic control over the network. It is expected to reduce the efficiency deterioration of RWA(Routing and Wavelength Assignment) due to the real-time variation of Internet traffic so that expandability and flexibility of the network can be enhanced. In this paper, we describe a methodology for traffic behavior analysis at a node, and the decision policy of the establishment/release of optical path. In addition, we evaluate the performance of the proposed scheme through the computer simulations.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.17 no.8 s.111
• /
• pp.725-731
• /
• 2006

A novel design of frequency multiplier using a feedforward technique and a defected ground structure(DGS) is proposed. The feedforward loop in the proposed frequency multiplier suppresses the fundamental component $(f_0)$, the dumb-bell or spiral shaped DGS diminish unwanted harmonics such as second, third and fourth. Due to the combination of the feedforward structure and the DGS, only the multiplied frequency component$(2f_0,\;3f_0,\;4f_0)$ appears at the output port and the other unwanted components are suppressed excellently. The frequency multiplier is designed at 1 GHz $(f_0)$, by the proposed technique and measured. The measured output power of $2f_0,\;3f_0$ and $4f_0$ is -2.59 dBm, -5.36dBm and -4.57dBm, respectively, when the input power is 0dBm.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.16 no.12 s.103
• /
• pp.1186-1193
• /
• 2005

In this paper, a new 3 dB branch line hybrid using asymmetric spiral-shaped defected ground structure(DGS) microstrip is proposed. The proposed branch line hybrid suppresses the 2nd and the 3rd harmonic component effectively. Also a DGS $\lambda$/4 bias line that can suppress high frequency harmonics as well as low frequency intermodulation component is proposed. With the harmonic termination tuner using the proposed hybrid and the harmonic blocking bias line, the 2nd and the 3rd harmonic components of the fabricated amplifier that operated in IMT-2000 basestation transmitting band were suppressed up 25 dB and 27 dB, respectively. The proposed harmonic load-pull setup of amplifier is more easily accomplished with proposed circuits than the previous.

• Archives of Craniofacial Surgery
• /
• v.19 no.1
• /
• pp.13-19
• /
• 2018

Background: $Abb{\acute{e}}$ flap technique is one of the most challenging operations to correct horizontal deficiencies in secondary cleft lip deformity. Since its first introduction, the operative method was dynamically modified from simple variation to complete conceptual change, but conventional $Abb{\acute{e}}$ flap has many drawbacks in esthetic and functional aspect. Our purpose was reconstructing the symmetry of Cupid's bow and central vermilion tubercle with minimal sequalae. Methods: From 2008 to 2016, this technique was applied to 16 secondary cleft lip patients who had total or more than 60% of unilateral deficiency of Cupid's bow and central lip or tubercle pouting deficiency. A quadrangular-shaped flap was transferred from vermilion including skin and white line of central or contralateral lower lip. Pedicle division and insetting were made at 9 (unilateral) or 10 (bilateral) days after transfer. Secondary lip revision was done with open rhinoplasty after wound maturation. Results: Overall satisfaction was high with modified technique. Scar was minimally noticeable on both upper and lower lip especially. Balanced Cupid's bow and symmetric vermilion tubercle were made with relatively small size of flap compared to conventional $Abb{\acute{e}}$ flap. An accompanying benefit was reduced ectropion of lower lip, which made balanced upper and lower lip protrusion with more favorable profile. Conclusion: A new modified $Abb{\acute{e}}$ flap technique showed great satisfaction. It is worth considering in secondary cleft lip patient who has central lip shortage and asymmetry of upper lip vermilion border line. Our technique is one of the substitutes for correction of horizontal and central lip deficiency with asymmetric Cupid's bow.

• Proceedings of the Korea Crystallographic Association Conference
• /
• 2003.05a
• /
• pp.8-8
• /
• 2003

Electron-phonon interaction plays a significant role in forming of colossal magnetoresistance effect (CMR). Polaron formation was observed by neutron diffraction and by extended X-ray absorption fine structure (EXAFS) analysis. Local probe as given by the EXAFS is a useful method to study the polaronic charge and its dependence on temperature and ions size. Here we present the EXAFS study of polaronic charge in La/sub 0.7/Ca/sub 0.3-X/Ba/sub X/MnO₃ compositions. The single phase La/sub 0.7/Ca/sub 0.3-X/Ba/sub X/MnO₃ manganites (x=0; 0.03; 0.06, ..., 0.3) were prepared by ceramic technology [1]. The Curie temperature was determined by extrapolation of the temperature dependence of the magnetization (down to zero magnetization). EXAFS experiments were carried out at the 7C EC beam line of the Pohang Light Source (PLS) in Korea. The atomic pair distribution functions (PDF) were obtained by re-regularization method [2] from filtered spectra. The PDF for the x=0.3 sample showed a single peak function and for x=0.0, 0.03, 0.06, 0.09, 0.12 compositions were asymmetric in agreement with a small Jahn-Teller elongation of two (short and long) bonds of the MnO/sub 6/ octahedron. Dispersion, σ/sub Min-O//sup 2/, and asymmetry, σ/sub Min-O//sup 3/, of the Mn-O bond distances varied significantly with x and showed a maximums at x=0.09. The maximum of σ/sub Min-O//sup 2/ is caused by increase of dynamic rms displacements of the Mn-O distances near the T/sub C/. The observed x dependence of σ/sub Min-O//sup 3/ reflects the reduction of charge carriers mobility at approaching to T/sub C/ from low as well as high temperatures.

• Molecules and Cells
• /
• v.19 no.3
• /
• pp.398-401
• /
• 2005

The bacterial enzyme UDP-N-acetylglucosamine enolpyruvyl transferase catalyzes the first committed step of peptidoglycan biosynthesis, i.e., transfer of enolpyruvate from phosphoenolpyruvate to UDP-N-acetyl-glucosamine. We have overexpressed the enzyme from Haemophilus influenzae in Escherichia coli and crystallized it in the apo-form, as well as in a complex with UDP-N-acetylglucosamine and fosfomycin using ammonium sulfate as the precipitant. X-ray diffraction data from a crystal of the apo-form were collected to $2.8{\AA}$ resolution at 293 K. The crystal quality was improved by co-crystallization with UDP-N-acetylglucosamine and fosfomycin. X-ray data to $2.2{\AA}$ have been collected at 100 K from a flash-frozen crystal of the complex. The complex crystals belong to the orthorhombic space group I222 (or $I2_12_12_1$) with unit-cell parameters of a = 63.7, b = 124.5, and $c=126.3{\AA}$. Assuming a monomer of the recombinant enzyme in the crystallographic asymmetric unit, the calculated Matthews parameter ($V_M$) is $2.71{\AA}^3Da^{-1}$ and solvent content is 54.6%.

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

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.10
• /
• pp.6084-6091
• /
• 2014

This paper presents the GJR GARCH model (Glosten et. al, 1993) to analyze the influences of volume volatilities on price volatilities in the fishery market. For the analysis, this study used the monthly price and volume data of aquacultural flatfish in Jeju. As a result, empirical analysis suggested volatility clustering. The persistency parameter(${\lambda}$) was estimated to be approximately 1 in aquacultural flatfish. The results showed that there is a significant negative relationship between the conditional variance of supply and that of price for aquacultural flatfish. This means that the general law of supply is valid. Finally, the empirical analysis was that an asymmetric coefficient (${\gamma}$) of GJR GARCH model was negative (-). This means that the higher volatility of volume leads to lower price volatility. That is, it is useful to make government policies that can adjust the volume (stockpiling, stabilizing supply and demand).

• Korean Journal of Materials Research
• /
• v.19 no.7
• /
• pp.369-375
• /
• 2009

The spot weldability of dissimilar metal joints between stainless steels (AISI316) and interstitial free (IF) steels were investigated. This study was aimed to determine the spot welding parameters for a dissimilar metal joint and to evaluate the dissimilar metal joint's weldability, including its welding nugget shape, tensileshear strength, hardness, and microstructure. The fracture surface was investigated by using a Scanning Electron Microscopy (SEM). The experimental results showed that the shape of nugget was asymmetric, in which the fusion zone of the STS316 sheet was larger due to the higher bulk-resistance. The microstructure of the fusion zone was fully martensite. In order to evaluate the microstructure further, dilution of stainless steels were calculated and imposed onto the Schaeffler diagram. The predicted microstructure from the Schaeffler diagram was martensite. In order to confirm the predicted microstructure, XRD measurements were carried out. The results showed that that initial weld nugget was composed of austenite and martensite.

• Journal of Advanced Navigation Technology
• /
• v.25 no.1
• /
• pp.84-89
• /
• 2021

The alternative method for symmetric configuration in optical link consisted of dispersion management and optical phase conjugation for compensating of the distorted optical signals due to chromatic dispersion and nonlinear effects of standard single mode fiber is proposed. The symmetric configuration means number of fiber spans, dispersion distribution in former half section and latter half section, etc should be symmetrical about optical phase conjugator. In dispersion-managed proposed in this research, optical phase conjugator is located after former half section consisted of 6 fiber spans and before latter half section of 14 fiber spans, and the averaged residual dispersion per span (RDPS) of each half section are consistence. The compensation effects of the distorted signals in the proposed link is analyzed by comparing with the results obtained in dispersion-managed link with the unequally averaged RDPS of each half section. From the simulation results, it is confirmed that RDPS deviation between adjacent fiber span has a grater effect on the compensation than the equivalent of the averaged RDPS.