• Korean Journal of Environment and Ecology
• /
• v.26 no.3
• /
• pp.342-347
• /
• 2012

This study was conducted to demonstrate the relationship between experience of cannibalism and difference of phenotype in the Korean salamander Hynobius leechii from March to April 2011. We examined whether the different polyphenism of larval salamander is induced as a result of indirect cannibalism in early life cycle. We divided into two groups(one group continuously exposed to the indirect cannibalism and the other group never exposed to the cannibalism). We measured the head width at the level of eyes(HWE), the largest head width(LHW) and snout-vent length(SVL) of the each larva then calculated the ratio of the head size by dividing HWE by LHW. We found that exposure of indirect cannibalism in early life cycle cause the different polyphenism. Our result means the larval salamander responded to the chemical cue from conspecific.

• Journal of Welding and Joining
• /
• v.32 no.4
• /
• pp.46-54
• /
• 2014

In this study, the effect of bonding temperature and bonding pressure on deformation and tensile properties of diffusion bonded joint of STS304 compact heat exchanger was investigated. The diffusion bonds were prepared at 700, 800 and $900^{\circ}C$ for 30, 60 and 90 min in pressure of 3, 5, and 7 MPa under high vacuum condition. The height deformation of joint decreased and the width deformation of joint increased with increasing bonding pressure at $900^{\circ}C$. The ratio of non-bonded layer and void observed in the joint decreased with increasing bonding temperature and bonding pressure. Three types of the fracture surface were observed after tensile test. The non-bonded layer was observed in diffusion bonded joint preformed at $700^{\circ}C$, the non-bonded layer and void were observed at $800^{\circ}C$. On the other hand, the ductile fracture occurred in diffusion bonded joint preformed at $900^{\circ}C$. Tensile load of joint bonded at $800^{\circ}C$ was proportional to length of bonded layer and tensile load of joint bonded at $900^{\circ}C$ was proportional to minimum width of pattern. The tensile strength of joint was same as base metal.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.10
• /
• pp.2245-2251
• /
• 2013

In this paper, a design of a compact series-fed dipole pair(SDP) antenna with end-loaded rectangular patches is presented. In order to reduce the lateral size of a conventional SDP antenna, rectangular patches are end-loaded to the two dipole elements of the SDP antenna and a grooved ground plane is used by adding a patch at both ends of the ground plane. The effects of varying the length and width of the rectangular patches on the antenna performance such as input reflection coefficient are investigated. An optimized compact SDP antenna covering a frequency band ranging from 1.7 GHz to 2.7 GHz is designed and fabricated on an FR4 substrate. The total width of the fabricated prototype of the proposed antenna is reduced by approximately 14.3% compared to the conventional SDP antenna. Experimental results show that the antenna presents a 48.7% bandwidth in the range of 1.68-2.76 GHz and a stable gain of 5.6-6.0 dBi with minimal degradation. Moreover, a front-to-back ratio is improved by about 0.7 to 7.4 dB.

• Journal of Ecology and Environment
• /
• v.39 no.1
• /
• pp.71-80
• /
• 2016

The main goal of this study is to develop a multi-metric fishway assessment model (M_m-FA) and evaluate the efficiency of fishway. The M_m-FA model has three major fishway components with nine metrics: structural characteristics, hydraulic/hydrologic features, and biological attributes. The model was developed for diagnosing and assessing fishway efficiency and tested to Juksan Weir at the Yeongsan River Watershed. Structural characteristics of fishway included slope of the fishway (M₁), ratios of fishway width to stream width (M₂), and the proportion of orifice clogging and orifice size (M₃). Hydraulic/hydrologic characteristics included depth of fishway entrance head (M₄), depth of exit tail (M₅), and current velocity of inner fishway (M₆). Biological characteristics included fish species ratio of inner fishway to upper-lower weir (M₇), fish length distribution (M₈), and the proportion of migratory fish species to the total number of species (M₉). Overall, the assessment of fishway efficiency showed the total score of the M_m-FA model was 25 in the Juksan Weir, indicating "good condition" by the criteria of the five-level classification system. The M_m-FA model may be used as a key tool for the assessment of fishway efficiency, especially on the 16 weirs constructed for the "Four Rivers Restoration Project" after a partial calibration of M_m-FA model.

• Journal of the Korean Society of Costume
• /
• v.25
• /
• pp.5-20
• /
• 1995

The fashion of late Yi dynasty had explored a possibility of new fashional beauty from its own experiences throughout the history of Korean fashion excluding any interference of foreign fashions, and brought out some characteristics ; first, the aesthetical value focused on the more human fashion resulted in the exposure of waist. This aesthetical change in the fashion of late Yi dynasty produced out results as follows ; the length and width of jacket became short and narrow maintaining the basic form, while the width of skirt became increased to be contrasted exceptionally with the upper coat. This mode of fashion reveals the transitional movement from the emphasis on balance to that on unbalance in the late period of Yi dynasty. But regarding the fact that the proportional change by the ways of putting on skirt became to be similar to the golden ratio, we can see many examples throughout the folk paintings by Shin Yun bok, we find that the fashional beauty of that age pursued ideal harmony and unity all the time being in spite of its tendency toward non-refinement. Second, we see another peculiarity in the mode of woman's fashion from the paintings by Shin Yun-bok who always depicted the hu-man nature frankly. For example, the jacket became shorter to emphasize lady's slim waist, and underwears began to be exposed after the upper part of skirt had been to expose lady's waist while the bottom line pulled up highter than before. Thus, as the function of robe had changed from a mere means of covering into an expression of beauty, the fashion of late Yi dynasty began to express a perfectly new beauty possessing an erotic mood and sensu-ality of a woman, which was its inner aesthetic need. Third, this emergence of new fashional beauty made the mental value of man and the aesthetic views of that time quite different from the previous ones, and finally there came various expressions of a new beauty. There-fore, the woman's fashion of late Yi dynasty is noted for the exposure and emphasis on the body line of a woman after the aesthetic view-point had changed of time toward pragmatism and humanism, while upholding the traditions of Korean clothes and pride for the nation. And our ancestors realized very Korean fashional beauty by pursuing the expressional ways of gentle, indirect emphasis upon the feminine and natural beauty to exclude and ar-tificial, direct and straightforward exposures and images.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.6A
• /
• pp.337-345
• /
• 2012

A model test is performed to investigate the dynamic behavior of truss type lift gate which is being constructed by the four major rivers project. The gate dimensioned 40 m in width, 9m in height is scaled with the ratio of 1:25 and is made of acryl panel and supplemented weight by lead in the concrete test flume dimensioned 1.2 m in width, 0.5 m in height and 30m in length. Firstly natural frequencies of the model gate are measured and compared with the numerical results for the calibration. The amplitudes of the vibration are measured under the different gate opening, upstream water level conditions. Also models with bottom angle $20^{\circ}$, $35^{\circ}$ and $50^{\circ}$ are tested and compared to find out a proper shape of bottom structure which minimizes the gate vibration. These test results presents a basic data for the guide manuals of gate management and a design method to reduce the gate vibration of truss type lift gate.

• Korean Journal of Plant Taxonomy
• /
• v.42 no.2
• /
• pp.126-140
• /
• 2012

We conducted principal component analyses using the thirty two quantitative characteristics of Najas from South Korea to examine the morphological variation and diagnostic characteristics. As a result of our investigation and the morphometric analyses, each taxon could be identified using the leaf width, shape of the leaf sheath, number of teeth on the leaf margin, number of anther cells, number of areoles in each longitudinal row of seeds, and the ratio of the areole width to the length. Dioecious Najas marina was clearly distinguished from the other monoecious taxa (N. graminea, N. gracillima, N. minor, N. oguraensis, and N. orientalis) by the larger size of the stem, the leaf, the flower and the fruit. The monoecious taxa could be identified using vegetative characteristics except for N. minor and N. oguraensis, which were distinct from each other according to the locule number in the staminate flower.

• Journal of Advanced Marine Engineering and Technology
• /
• v.37 no.5
• /
• pp.510-519
• /
• 2013

In this study, the spray characteristics of a pressure swirl atomizer classified into a liquid sheet-type swirl nozzle for Urea-SCR system were investigated experimentally with the variation of injection pressure. The length to diameter ratio ($l_o/d$) of the nozzle was 3.1, and the swirler was set inside the nozzle tip to give injecting fluid angular momentum. The injection duration of the nozzle was controlled by PWM (pulse width modulation) modes. The development processes of the spray were imaged by a 2-D PIV system, and the change of spray angle was measured. The atomization characteristics, including axial velocity and SMD, were measured using a 2-D PDA system with the injection pressures at room temperature and ambient pressure conditions. As the experimental results, the injection pressure had a significant impact on the spray structure showing a different shape around the spray leading edge, and the smaller SMD was observed with increasing injection pressures, which was similar to that of the previous work.

• Journal of Korea Water Resources Association
• /
• v.48 no.2
• /
• pp.137-147
• /
• 2015

This study performed the systematic classification of the various types of riffles and analyzed their physical and hydraulic characteristics at the Hongcheon River and Seomjin River. The riffles are classified into the long type and the wide type by their ratio of length and width, and also classified into the convergent type and the divergent type by their width change along flow direction. They are also classified into the falling type, the running type, the undular wave and the undular jump by their surface profiles. The falling type and the running type usually occur near the cobbles with multiple diameters, whereas the undular wave and the undular jump occur near the small pebbles. They showed the upward convex type at the middle part, and the slope gets bigger at the downstream part.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.51 no.6
• /
• pp.229-235
• /
• 2002

This paper presents the fabrication of polycrystalline thin film transistor(TFT) using sequential lateral solidification(SLS) of amorphous silicon. The fabricated SLS TFT showed high Performance suitable for active matrix liquid crystal display(AMLCD). The SLS process involves (1) a complete melting of selected area via irradiation through a patterned mask, and (2) a precisely controlled pulse translation of the sample with respect to the mask over a distance shorter than the super lateral growth(SLG) distance so that lateral growth extended over a number of iterative steps. The SLS experiment was performed with 550$\AA$ a-Si using 308nm XeCl laser having $2\mu\textrm{m}$ width. Irradiated laser energy density is 310mJ/$\textrm{cm}^2$ and pulse duration time was 25ns. The translation distance was 0.6$\mu$m/pulse, 0.8$\mu$m/pulse respectively. As a result, a directly solidified grain was obtained. Thin film transistors (TFTs) were fabricated on the poly-Si film made by SLS process. The characteristics of fabricated SLS p -type poly-Si TFT device with 2$\mu\textrm{m}$ channel width and 2$\mu\textrm{m}$ channel length showed the mobility of 115.5$\textrm{cm}^2$/V.s, the threshold voltage of -1.78V, subthreshold slope of 0.29V/dec, $I_{off}$ current of 7$\times$10$^{-l4}$A at $V_{DS}$ =-0.1V and $I_{on}$ / $I_{off}$ ratio of 2.4$\times$10$^{7}$ at $V_{DS}$ =-0.1V. As a result, SLS TFT showed superior characteristics to conventional poly-Si TFTs with identical geometry.y.y.y.