• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.12
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• pp.2731-2740
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• 2012

ASIC(application specific integrated circuit) process is a set of various technologies for fabricating a chip. Generally there have been many researches for RTL design, synthesis, floor plan & routing, low power scheme, clock tree synthesis, and testability which are widely researched in recent. In this paper we propose a new methodology of power strap routing in basis of design experience and experiment. First the power strap for vertical VDD and VSS and horizontal VDD and VSS is routed, and then after the problems which are generated in this process are analyzed, we propose a new process for resolving them. For this, the strap guide is inserted to protect the unnecessary strap routing and dumped for next steps. Next the unnecessary power straps which are generated the first inserting process are removed, and the pre-routing is performed for the macro cells. Finally the resultant power straps are routed using the dumped routing guide. Through the proposed process we identified the efficient and stable route of the power straps.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.3
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• pp.509-516
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• 1999

In this paper, it is designed a microstrip U-slotted patch antenna with double resonances to enhance the bandwidth. In the design of an U-slotted patch antenna, there are considered the input impedance, the width of patch, the total length of the slot, the height of foam, the position of the probe and the radius of feed pin. The broadband behavior of antenna can be obtained by adjusting the length and width of the slot. The radiation from the antenna is linear polarized with the E-paine parallel to the vertical slots and the H plane parallel to horizontal slot. The radiation pattern, impedance locus, and VSWR of the antenna are calculated using "ENSEMBLE" software, and compared with the experimental results. Experimental results show that the bandwidth for VSWR $\le$ 2:1 is about 28.6%, a directivity 14.18dBi at 6.040GHz. 6.040GHz.

• Journal of the Korean Geosynthetics Society
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• v.3 no.1
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• pp.3-15
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• 2004

Geogrid reinforced soil structures with segmental block facing have been increased since 1990's, because of the convenience of installation and the flexible appearance. In this paper, the behavior of the segmental reinforced retaining wall was analysed with the results of field monitoring. The height and length of reinforced wall are 12m and 25m, respectively. The field measurement equipments are horizontal and vertical earth pressure cells, settlement plate, strain gauge, inclinometer, and displacement pin. Based on the field monitoring, the horizontal earth pressure was approximately 0.3times higher than that of the theoretical method and the maximum tensile strength of reinforcement was 26.2kN/m. The displacement of facing wall was 23mm at the point of 7.1m height of the wall and toward the wall facing. The results of the study indicate that the segmental reinforced retaining wall is in a stable condition because of good compaction & reinforcement effects, and long period of construction time. Finally, the computer program of SRWall is very useful tool to design the segmental reinforced retaining wall.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4121-4128
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• 2010

A probe card is used in testing semiconductor wafers. It must maintain a precise location tolerance for a fine pitch due to highly densified chips. However, high heat transferred from its lower chuck causes thermal deformations of the probe card. Vertical deformation due to the heat will bring contact problems to the pins in the probe card, while horizontal deformation will cause positional inaccuracies. Therefore, probe cards must be designed with proper materials and structures so that the thermal deformations are within allowable tolerances. In this paper, heat transfer analyses under realistic loading conditions are simulated using ANSYS$^{TM}$ finite element analysis program. Thermal deformations are calculated based on steady-state temperature gradients, and an optimal structure of the probe card is proposed by adjusting a set of relevant design parameters so that the deformations are minimized.

• Journal of the Korean Arthroscopy Society
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• v.6 no.2
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• pp.195-199
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• 2002

This article is to report a new technique for reconstruction of the anteromedial and posterolateral bundles of anterior cruciate ligament by separate tensioning and fixation of the each bundle. Method : Tibial and femoral tunnels were made with conventional technique of anterior cruciate ligament reconstruction. Tibial tunnel was enlarged $5\~7$ mm in anterior-posterior direction to make oval it in cross section. When preparing the Achilles tendon allograft, bone plug portion was trimmed as the conventional technique. The tendinous portion was trimmed as two separate bundles by dividing the tendinous portion longitudinally, so the graft is shaped like 'Y'. The bone plug portion of allograft was inserted into the femoral tunnel and fixed with absorbable cross pins. Two ligamentous portionss of the distal part of the grafts were tensioned separately at the external orifice. Anteromedial bundle was fastened under maximum tension with the knee flexed 90 degrees by post-tie method. The posterolateral bundle was fixed by the same technique with the knee in full extension. Then, an absorbable interference screw was inserted between the two bundles upto the upper end of the tibial tunnel, to get more initial rigidity of the reconstructed graft as well as to locate the two bundles in more anatomic position.

• Journal of Korean Society of Steel Construction
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• v.18 no.4
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• pp.437-446
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• 2006

Open-steel-plate-girder(OSPG) bridges are one of the most prevalent bridge types among Korean railway bridges. They account for about 40% of all Korean railway bridges. However, the line-type bearings used for OSPG bridges generate several problems with respect to the bridges' dynamic behavior and maintenance. The replacement of the existing bearings with polyurethane disk bearings could be a possible solution to this problem. This type of disk bearing is an elastic bearing using a polyurethane disk. This study estimated the variations in the natural frequency of a bridge when disk bearings were installed and the bridge's dynamic behavior with a running locomotive and running trains. The first natural frequency of the bridge was 3% lower than that of the as-built bridge after the installation of the disk lower, respectively. Also, the second and third frequencies were 7 and 15% lower, respectively. The disk bearings increased the vertical displacement of the bridge, but the pure displacement, excluding the disk deformation, did not vary. The vertical acceleration did not increase when the disk bearing was installed, with trains running. The shear pin in the disk bearing reduced the lateral displacement and the acceleration of the bridge.

• The Korean Journal of Physiology
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• v.24 no.1
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• pp.1-13
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• 1990

The effects of electrolytes, adenosine, ATP, 5-hydroxytryptamine (5-HT, serotonin) and ketanserin on the inhibitory junction potentials (IJPs) were investigated to clarify the interactions of these drugs with the neurotransmitters released from non-adrenergic, non-cholinergic nerves in the antrum of guinea-pig stomach. Electrical responses of antral circular muscle cells were recorded intracellularly using glass capillary microelectrode filled with 3 M KCI. All experiments were performed in Tris-buffered Tyrode soluition which was aerated with 100% $O_{2}$ and kept at $35^{\circ}C$. The results obtained were as follows: 1) Inhibitory junction potential (IJP) was recorded in antral strip, while excitatory junction potential (EJP) was recorded in fundic strip. 2) IJP recorded in antral strip was not influenced by atropine $(10^{-6}\;M)$ and guanethidine $(5{\times}10^{-6})$. 3) The amplitude of IJP increased in high $Ca^{2+}$ solution, while that of IJP decreased in high $Mg^{2+}$ solution or by $Ca^{2+}$ antagonist (verapamil). Apamin, $Ca^{2+}$-activated $K^{+}$ channel blocker blocked IJP completely. 4) ATP and adenosine decreased the amplitude of IJP. 5) 5-HT decreased the amplitude of IJP with no change of the amplitude of slow waves, while ketanserin (5-HT type 2 blocker) decreased the amplitude of slow waves markedly with no change in that of IJP. From the above results, the following conclusions could be made. 1) IJP recorded in antral strip is resulted from neurotransmitters released from non-adrenergic, non-cholinergic nerves. 2) An increase in the concentration of external $Ca^{2+}$ enhances the release of neurotransmitters from non-adrenergic, non-cholinergic nerves which activate the $Ca^{2+}$-dependent $K^{+}$ channel.