• Journal of Korea Water Resources Association
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• v.46 no.9
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• pp.947-956
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• 2013

Most of flood protection walls built on the impingement in mountain rivers have been made of concrete. It may cause flood disasters because the smooth wall surface could increase flow velocity. In this study the hydraulic experiments was carried out to evaluate the effect of one side wall with rectangular vertical ribs on flow resistance in open channel. The ratio of the pitch between vertical ribs to its depth, ${\lambda}_{nv}$, was designed so that it include the so-called d type and k type roughness. The range of Froude number, $F_r$, based on hydraulic radius is 0.81~1.12. Flow resistance in the open channel with a rib sidewall depends on the interval length of each ribs and the flow discharge. Maximum flow resistance occurred when ${\lambda}_{nv}$ is 9. In the d type roughness which ${\lambda}_{nv}$ is less than 3, the flow resistance decreases with increase of flow discharge. In the k type roughness which ${\lambda}_{nv}$ is greater than 3, the flow resistance increases with increase of flow discharge. The increments of flow resistance are especially great when ${\lambda}_{nv}$ are 9 and 12. The resistance due to vertical rib is mostly by the shape resistance and the vertical rib on one sidewall of open channel affects on the flow resistance so that the equivalent roughness heights of vertical rib may occur in scale of flow depth. Therefore the vertical ribs may be used to reduce the flow velocity and to move the location of maximum flow velocity from the rib sidewall to the centerward in a cross section of channels.

• Proceedings of the Korean Fiber Society Conference
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• 2002.04a
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• pp.367-370
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• 2002

PET, 나일론 등과 같이 타이어코드용으로 사용되는 섬유는 타이어 내에서 계속적인 신장, 굽힘 및 압축변형을 받기 때문에 이들로 인하여 내피로성이 아주 중요한 의미를 가진다. 일반적으로 타이어는 Tread, Bead, Carcass, Sidewall, Belt 등으로 구성되어 있는데, 여기에서 타이어 코드용 섬유는 타이어의 뼈대를 이루는 것으로 타이어의 성능과 수명을 좌우하는 아주 중요한 소재인 것이다[1-2]. (중략)

• Carbon letters
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• v.26
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• pp.61-65
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• 2018

Comprehensive calculations of the Rh decoration effect on zigzag CNTs with n ranging from 7 to 12 were conducted in this work to understand the effect of Rh doping on geometric structures and electronic behaviors upon metallic and semiconducting CNTs. The obtained results indicated that Rh dopant not only contributes to the deformation of C-C bonds on the sidewall of CNTs, but also transforms the electron distribution of related complexes, thereby leading to a remarkable increase of the conductivity of pure CNTs given the emerged novel state within the energy gap for metallic CNTs and the narrowed energy gap for semiconducting CNTs. Our calculations will be meaningful for exploiting novel CNT-based materials with better sensitivity to electrons and higher electrical conductivity compared with pure CNTs.

• Journal of the Korean Geotechnical Society
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• v.20 no.5
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• pp.59-66
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• 2004

This study compared the reinforcing effect of sand by Geocell to those of newly devised Tirecell$^{\circledR}$ made by waste tires, tire mat by sidewalls of tires. Plate loading tests in a large chamber were conducted for different reinforcing materials at the same conditions of relative density, embedded depth of sand. The combination of Tirecell and sidewall gives the highest increase of bearing capacity and reduction of settlement. The Geocell with the same height of Tirecell gives similar reinforcement effect to the tire mat made by sidewalls.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.364-371
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• 2004

This study presented the reinforcing effect of sands by newly devised $Tirecell^{(R)}$ made by waste tires, tire mat by sidewalls of tires and Geocell. Plate loading tests were conducted for different reinforcing materials at the same condition. The combination of Tirecell and sidewall gives the highest increase of bearing capacity and reduction of settlement. The Geocell with the same hight of Tirecell gives similar reinforcement effect to the tire mat made by sidewalls.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.5
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• pp.761-778
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• 2017

The need of the underground space for the infrastructures in urban area is increasing, and especially the demand for shallow tunnels increased drastically. It is very important that the shallow tunnel in the urban area should fulfill not only its own safety conditions but also the safety condition for the adjacent structures and the surrounding sub-structure. Most of the studies on the behavior of shallow tunnels concentrated only on their behaviors due to the local deformation of the tunnel, such as tunnel crown or tunnel sidewall. However, few studies have been performed for the behavior of the shallow tunnel due to the deformation of the entire tunnel. Therefore, in this study the behavior of the surrounding ground and the stability caused by deformation of the whole tunnel were studied. For that purpose, model tests were performed for the various ground surface slopes and the cover depth of the tunnel. The model tunnel (width 300 mm, height 200 mm) could be simulationally deformed in the vertical and horizontal direction. The model ground was built by using carbon rods of three types (4 mm, 6 mm, 8 mm), in various surface slopes and cover depth of the tunnel. The subsidence of ground surface, the load on the tunnel crown and the sidewall, and the transferred load near tunnel were measured. As results, the ground surface subsided above the tunnel, and its amount decreased as the distance from the tunnel increased. The influence of a tunnel ceased in a certain distance from the tunnel. At the inclined ground surface, the wider subsidence has been occurred. The loads on the crown and the sidewall were clearly visible, but there was no effect of the surface slope at a certain depth. The load transfer on the adjacent ground was larger when the cover depth (on the horizontal surface) was lager. The higher the level (on the inclined surface), the wider and smaller it appeared. On the shallow tunnel under inclined surface, the transfer of the ambient load on the tunnel sidewall (low side) was clearly visible.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.298-304
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• 2012

The development of low rolling resistance tire with weight reduction in tire and vehicle may induce high level of tire/road noise, especially the rumble road noise on rough road. In this paper, the design factor for good rumble noise is considered in view of tire and vehicle. For the 3 mid-sized sedans, the rumble noise is very sensitive to the test vehicle. And it is concluded that the tire with high tread part stiffness and low sidewall part stiffness shows best rumble noise performance, and the rumble noise is in trade-off relation with cavity resonance noise. So, it is desirable to select and change proper construction design factors to have good tire/vehicle rumble noise.

• Journal of the Korean institute of surface engineering
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• v.29 no.6
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• pp.869-875
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• 1996

In this article the effects of process parameters of inductively coupled plasma etching with $SF_6$ /$N_2$/Ar mixture gas and mask materials on the etched profile of W were investigated. While the etched profile was improved by $N_2$-addition, low working presure, and reduced $SF_6$ flow rate, the etching selectity (W against SAL resist) was decreased. Due to the difficulty of W etching with single layer resist, sputter deposited $Al_2O_3$ film was used as a hardmask. Reduction of required EB resist thickness through $Al_2O_3$ mask application could reduce proximity effect during e-beam patterning, but the etch anisotropy was degraded by decreased sidewall passiviation effect.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.93-96
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• 1996

We developed three dimensional Monte carlo ion implantation simulator which simulate distributions of impurities under the ion implantation on the tilted multi-layered layer. Our simulation reveals three dimensional shadow effect and sidewall scattering effect due to the geometrical shapes. For the evaluation of the developed three dimensional Monte carlo ion implantation simulator, calculations with 100,000 ions have been performed for the island and hole structures with a thin oxide of 100$\AA$ and nitride of 2000$\AA$. The simulation results showed that the distribution of ion decreases near the conner of the hole structure covered with a nitride layer and increases near the conner for the island structure open to oxide. Moreover, three dimensional distributions of ions were obtained with varying incident energy, tilt and rotation angle, mask depth and three-dimensional structure geometry.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.284-285
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• 2007

In this paper, we present the effect on a novel transmission line filter response by the etch hole position on the suspended ground and the residue on the resonator under ground plane. We defined the etch hole offset as the distance from the sidewall of the suspended ground to the nearest side of the etch holes. We simulated new filter responses to reflect the real value of the changed etch hole offset caused by characteristics of negative photoresist. Return loss is distorted by the residue on the center conductor remained after sacrificial layer removing. By comparison of simulation and measurements, we concluded the residue on the resonator distorted the RF response worse than etch hole offset variation did.