• Journal of the Korean Geographical Society
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• v.39 no.1
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• pp.45-55
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• 2004

The paper describes the rainfall-runoff. soil moisture distribution and subsurface flow of 'U-shaped Goll' valley head slope to evaluate quantitatively the interaction between the water circulation system and geomorphic development. The findings are as follows: The fissure and the pipe entrance in front of 'U-shaped Goll' introduce a lot of direct runoff into either the soil pipe or the soil layer to accelerate the erosion of the soil layer, so that they are likely to contribute to the expansion and development of the soil pipe. Most of soil water is to be drained in pipe flow, while some of remaining soil water is to be fed into groundwater. Therefore, low rainfall intensity is thought to let both the groundwater level and the pipe flow react sensitively by the effects of the precedent rainfall even at events: As a result, the soil pipe is said to be an important factor having influence upon the material balance of 'U-shaped Goll' valley head slope. On the other hand, the groundwater shows greater specific flux at the top than at the bottom, and relatively larger specific flux is applied to the top to make 'U-shaped Goll' valley head slope go back to the top.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.7
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• pp.828-833
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• 2007

A small monopole antenna with a novel impedance matching structure is proposed in this paper. The proposed antenna is designed for W-LAN(IEEE 802.11b). The antenna design concept is based on a ${\lambda}/8$ folded monopole antenna with a self-impedance matching structure. The size of the proposed antenna is smaller than the resonant length, thus the impedance at the terminal of the antenna becomes very capacitive. To compensate fur this impedance mismatching, the proposed antenna employs a novel self-impedance matching structure. The self-impedance matching structure is located on the top of the antenna; it improves the impedance matching and ultimately the efficiency of the antenna. The measured results of the proposed antenna show reasonable agreement with prediction.

• Fire Science and Engineering
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• v.27 no.6
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• pp.89-96
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• 2013

The purpose of this study is to check the fire origin and cause of the fire by observing the shape of the flame propagation in air-conditioner indoor unit through the fire tests. We supposed that the flame is spread from the surroundings to the top of the air-conditioner and ignited on top of the air-conditioner with n-heptane. And then repeated this experiment twice under the same conditions. After the ignition, refrigerant filled in air-conditioner and lubricating oil exploded with large explosion and flame having high temperature and pressure belched out rapidly due to bursting refrigerant pipe linked air-conditioner between 734 seconds and 559 seconds. After result of checking the combustion residue we found that almost all of that was lost except a part of the evaporator, motor and metal. The position of short-circuit traces of wiring for the air-conditioner ignited itself is similar to that of fire damage by external flame. Therefore, we verified that it is not certain to determine the ignition cause and point by only the shape of the combustion residues.

• Archives of design research
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• v.14 no.4
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• pp.189-198
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• 2001

This study was to identify HCl design factors for increasing information processing and attention for mentally retarded children. Several factors such as size, location, moving distance were varied for three experiments operated by the amount of information. The results showed that the larger size of target, the greater moving distance of target, and the less amount of information increased mentally retarded children's sensitivity. Also, when the target was displayed at upper left of computer screen, sensitivity of mentally retarded children was high, compared other locations of screen.

• Journal of the Korean Institute of Gas
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• v.12 no.4
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• pp.34-40
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• 2008

Using the finite element method and Taguchi's design technique, the displacement in vertical direction, von Mises stress, and strain energy of the corrugation damper have been analyzed as functions of the extruded length and the thickness of the corrugation damper, and the upper and lower corner radii of the damper. The optimized profile design elements of a corrugation damper are very important for increasing a strain energy absorption capacity of a helmet structure, which is attacked by impulsive external forces. In this study, the optimized design data based on the Taguchi's method was computed as a corrugation damper length of L = 20 mm, a damper thickness of t = 2 mm, the upper corner radius of $R_1=4\;mm$, and the lower corner radius of $R_2=3\;mm$. The optimized design parameters of a corrugation damper indicated that the thickness and extruded length of a corrugation damper may affect to increase the strain energy, which absorbs the impact forces of the helmet.

• Journal of the Korean Geotechnical Society
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• v.16 no.4
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• pp.51-61
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• 2000

This paper reviews fundamentals of a pseudo-static seismic design/analysis method for soil-reinforced segmental retaining walls. A comparative study on NCMA and FHWA seismic design guidelines, which are one of the most well known design guidelines for mechanically stabilized earth walls, was also performed. The results demonstrate that there exist significant discrepancies in the results of external stability analysis despite the same calculation model used in the two guidelines, due primarily to different seismic coefficient selection criteria. It is also demonstrated that the internal stability calculation model for NCMA guideline tends to yield larger seismic reinforcement force in the shallower reinforcement layers, resulting in an increased number of reinforcement layers at the top of reinforced wall and increased reinforcement lengths to ensure adequate anchorage capacity. The internal stability calculation model adopted by FHWA guideline, however, leads to redistribution of dynamic force to the lower reinforcement layers and thus results n an opposite trend of NCMA guideline. Findings from this study clearly demonstrate a need for more in-depth studies to develop a generally acceptable design/analysis method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.9B
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• pp.581-590
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• 2005

The IEEE 802.17 Resilient Packet Ring Working Group develops standards to support the development and deployment of Resilient Packet Ring networks in Local, Metropolitan, and Wide Area Networks for resilient and efficient transfer of data Packets at rates scalable to many gigabits Per second. It was known that the fairness algorithm of the IEEE 802.17 Resilient Packet Ring suffers from throughput degradation under an unbalanced overload. This Paper proposes a congestion release advertisement method to improve this throughput degradation and discusses its performance. Under the proposed method, a congested node decides whether its congestion is released or not. If released, it advertises the congestion release to upstream nodes, and then upstream nodes transmit their traffic without uy regulation. The proposed method is compatible with the legacy fairness algorithm.

• Korean Journal of Optics and Photonics
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• v.28 no.6
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• pp.361-365
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• 2017

In this paper, we demonstrate a facile fabrication technique for a periodically aligned metal nanoparticle array, for a narrow-band plasmonic absorber. The metal nanoparticles are fabricated by e-beam evaporation and heat treatment processes on top of a periodic aluminum groove template. The plasmonic absorber is constructed with the transferred metal nanoparticle array, sputtered 33-nm-thick $Al_2O_3$, and 200-nm-thick metal reflector layers on silicon substrate. 46-nm-diameter and 76-nm-lattice metal-nanoparticle-array-based plasmonic absorber has performed as a narrow-band absorber with a central wavelength of 572 nm and full width at half maximum (FWHM) of 109.9 nm.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.4
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• pp.317-322
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• 1994

This study was conducted to increase the seed yield and to find the interaction of several characters of sesame on the reclaimed upland by application of minor nutrient which were boron, magnesium and zinc. A result of testing of boron and magnesium were effective relatively. Application of boron and magnesium were increased the dry stem wt. of upper capsule setting position, Specially dual application of boron and magnesium were remarkable. Dry stem wt. affected on seed increasing of lower and middle capsule setting part. Capsule no. per plant was showed higher degree in dual B+Mg than each application. Capsule no. affected on increasing of dry stem wt. as well as seed yield also. Capsule no. of lower and upper capsule setting part indicated relation with seed yield, 1000 grains weight. This result showed increasing tendency of upper capsule setting part in B+Mg+Zn application. The products of seed yield indicated the increasing of estimate production at the highest 21% in dual Mg+B, 17% of dual B+Zn+Mg secondly, 12% of single boron application thirdly.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.3
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• pp.225-232
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• 2014

In this study, a cooperative UAV and UGV platform is proposed to obtain a wide range of visual information. The UAV recognizes a pattern marker on UGV and tracks the UGV without user control. It can provide wide range of visual information for a user in the UGV. The UGV by a user is controled equipped with an aluminum board. And the UAV can take off and land on the UGV. The UAV uses two cameras; one camera is used to recognize a pattern marker and another is used to provide a wide range of visual information to the UGV's user. It is guaranteed that the proposed visual-based approach detects and tracks the target marker on the UGV, and then lands well. The experimental results show that the proposed approach can effectively construct a cooperative UAV/UGV platform for obtaining a wide range of vision information.