• Title/Summary/Keyword: hole connection

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A Case Study of Prediction and Analysis of Unplanned Dilution in an Underground Stoping Mine using Artificial Neural Network (인공신경망을 이용한 지하채광 확정선외 혼입 예측과 분석 사례연구)

  • Jang, Hyongdoo;Yang, Hyung-Sik
    • Tunnel and Underground Space
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    • v.24 no.4
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    • pp.282-288
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    • 2014
  • Stoping method has been acknowledged as one of the typical metalliferous underground mining methods. Notwithstanding with the popularity of the method, the majority of stoping mines are suffering from excessive unplanned dilution which often becomes as the main cause of mine closure. Thus a reliable unplanned dilution management system is imperatively needed. In this study, reliable unplanned dilution prediction system is introduced by adopting artificial neural network (ANN) based on data investigated from one underground stoping mine in Western Australia. In addition, contributions of input parameters were analysed by connection weight algorithm (CWA). To validate the reliability of the proposed ANN, correlation coefficient (R) was calculated in the training and test stage which shown relatively high correlation of 0.9641 in training and 0.7933 in test stage. As results of CWA application, BHL (Length of blast hole) and SFJ (Safety factor of Joint orientation) show comparatively high contribution of 18.78% and 19.77% which imply that these are somewhat critical influential parameter of unplanned dilution.

Study on the Relationship of Brain and Heart Based on Oriental Medicine (뇌(腦)와 심(心)의 한의학적 상관성에 대한 연구)

  • Jo Hak-Jun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.6
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    • pp.1496-1503
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    • 2005
  • This study aims to define the relationship between brain and heart through several literatures about oriental medicine and the conclusions are as follows. Heart in oriental medicine is called as Sinmyeongjishim(神明之心) which has a close connection with Mind, Consciousness, Emotion, and Physiological instinct of Drain in modern medicine. According to Oriental medicine, Brain stores Wonsin(元神) as Heart stores mind(神). Heart is where mind rests whereas Brain is where mind reveals. The external evidences that prove the relationship of Heart and Mind are as follows: First, with ears, eyes, mouth, and nose the subject of cognition is recognized as Sinmyeongjishim(神明之心). Second, Bulin(不仁), which means decreased movement power and sensibility of limbs, proves that Sinmyeongjishim(神明之心) is involved with movement power and sensibility of limbs. The physiological evidences that prove the relationship of Heart and Mind are as follows; First, Heart as the operation of Sinmyeongjishim(神明之心) manages language. Second, Heart is related with Tongue. Third, Heart is linked to Ears through the ear hole. Fourth, Heart is a store of Mind. Fifth, the five viscera control emotional and psychological activities. The pathological evidence of the relationship of Heart and Mind is that the symptoms of heart disease which are related to Sinmyeongjishim(神明之心) are also related to the functions of Brain. Though Brain has a close connection with Heart in oriental medicine, it is recognized that there are distinctive symptoms of disease of Brain and Hyeolyookjishim(血肉之心) respectively. The relationship of Heart and Brain has been researched in this study, even though there are not enough written materials about oriental medicine. But the fact that the majority of Heart operation is deeply connected with Brain activities cannot be denied. Therefore the research of Heart should be done as well as Brain in the clinical study of Brain.

The behaviour of a new type of connection system for light-weight steel structures applied to roof trusses

  • Kaitila, Olli;Kesti, Jyrki;Makelainen, Pentti
    • Steel and Composite Structures
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    • v.1 no.1
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    • pp.17-32
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    • 2001
  • The Rosette-joining system is a completely new press-joining method for cold-formed steel structures. One Rosette-joint has a shear capacity equal to that of approximately four screws or rivets. The Rosette thin-walled steel truss system presents a new fully integrated prefabricated alternative to light-weight roof truss structures. The trusses are built up on special industrial production lines from modified top hat sections used as top and bottom chords and channel sections used as webs which are joined together with the Rosette press-joining technique to form a completed structure easy to transport and install. A single web section is used when sufficient but can be strengthened by double-nesting two separate sections or by using two lateral profiles where greater compressive axial forces are met. An individual joint in the truss can be strengthened by introducing a hollow bolt into the joint hole. The bolt gives the connection capacity a boost of approximately 20%. A series of laboratory tests have been carried out in order to verify the Rosette truss system in practice. In addition to compression tests on individual sections of different lengths, tests have also been done on small structural assemblies and on actual full-scale trusses of a span of 10 metres. Design calculations have been performed on selected roof truss geometries based on the test results, FE-analysis and on the Eurocode 3 and U.S.(AISI) design codes.

Two-level control system of toggle braces having pipe damper and rotational friction damper

  • Ata Abdollahpour;Seyed Mehdi Zahrai
    • Structural Engineering and Mechanics
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    • v.86 no.6
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    • pp.739-750
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    • 2023
  • This study examines the two-level behavior of the toggle brace damper within a steel frame having a yielding pipe damper and rotational friction damper. The proposed system has two kinds of fuse for energy dissipation in two stages. In this mechanism, rotational friction damper rather than hinged connection is used in toggle brace system, connected to a pipe damper with a limited gap. In order to create a gap, bolted connection with the slotted hole is used, such that first a specific movement of the rotational friction damper solely is engaged but with an increase in movement, the yielding damper is also involved. The performance of the system is such that at the beginning of loading the rotational friction damper, as the first fuse, absorbs energy and with increasing the input load and further movement of the frame, yielding damper as the second fuse, along with rotational friction damper would dissipate the input energy. The models created by ABAQUS are subjected to cyclic and seismic loading. Considering the results obtained, the flexibility of the hybrid two-level system is more comparable to the conventional toggle brace damper. Moreover, this system sustains longer lateral displacements. The energy dissipation of these two systems is modeled in multi-story frames in SAP2000 software and their performance is analyzed using time-history analysis. According to the results, permanent relocations of the roof in the two-level system, in comparison with toggle brace damper system in 2, 5, and 8-story building frames, in average, decrease by 15, 55, and 37% respectively. This amount in a 5-story building frame under the earthquakes with one-third scale decreases by 64%.

An Experimental Study on the Stress Behavior of Coped Stringers in Steel Railway Bridge - II : Repair · Strengthening Method (철도교 세로보 절취부에서의 응력거동에 관한 실험적 연구 - II : 보수·보강 방법)

  • Li, Guang Ri;Park, Young Suk
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.4A
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    • pp.307-313
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    • 2009
  • In this study, in order to research the repair-strengthening methods, when fatigue crack occurs in the coped stringers of a steel railway bridge, we manufacture the full size of crossbeam-stringer and floor system model. Also the experimental test is performed on the coped stringers applying the repair-strengthening methods using the stop hole, combination plate, connection plate, bracket, and so on. The results indicate that, the most effective method is to set up connection plate and bracket in the top flange and bottom flange of the stringers, while we can consider the method of punching stop holes in the end of the crack as a subsidiary method. It is necessary to set up the combination plate when the length of crack is quite long.

The Study on the Physical Property of Provisional Prosthesis using Modified Temporary Abutment (변형된 임플란트 임시 지대주의 물성에 대한 연구)

  • Yang, Byung-Duk;Yoon, Tae-Ho;Choi, Un-Jae;Park, Ju-Mi
    • Journal of Dental Rehabilitation and Applied Science
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    • v.22 no.4
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    • pp.329-340
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    • 2006
  • Statement of problem: Damping of the peak force transmitted to implants has been reported by in vitro studies using impact forces on resin-veneered superstructures. Theoretical assumptions suggest that use of acrylic resin for the occlusal surfaces of a prosthesis would protect the connection between implant and bone. Therefore, the relationship between prosthesis materials and the force transmitted through the implant system also needs to be investigated under conditions that resemble the intraoral mechanical environment. Purpose: The purpose of this study was to analyze the fracture strength and modes of temporary prosthesis when a flange or occlusally extended structure were connected on the top of the abutment. Material and method: Modified abutments of winged and bulk design were made by casting the desired wax pattern which is made on the UCLA type plastic cylinder. Temporary crowns were made using templates on the modified abutments, and its fracture toughness and strain were compared to the traditional temporary prosthesis. To evaluate the effect of aging, 5.000 times of thermocycling were performed, and their result was compared to the 24hours specimen result. Results: The following conclusions were drawn from this study: 1. In the fracture toughness test, temporary crown's fracture line located next to the screw hole while modified designs with metal support showed fracture line on the metal and its propagation along the metal-resin interface. 2. Wing and bulk structure didn't show significant difference in the fracture toughness (p>0.05), but wing structure showed stress concentration on the screw hole area compared to bulk structure which showed even stress distribution. 3. In the fracture toughness test after thermocycling, wing and bulk structure showed increased or similar results in metal supported area while off-metal area and temporary crown showed decreased results. 4. In the strain measurement after thermocycling, its value increased in the temporary and bulk structure. However, wing structure showed decreased value in the loading point while increased value in the screw hole area. Conclusion: Wing type design showed compatible result to the bulk type that its application with composite resin prosthesis to the implant dentistry is considered promising.

Design of Meander Chip Antenna with Gap Stub for Dual-Band(GPS/K-PCS) Operation (갭 스터브가 삽입된 이중 대역(GPS, K-PCS) 미엔더 칩 안테나 설계)

  • Kim Young-Do;Sin Kyung-Sup;Won Chung-ho;Lee Hong-Min
    • Proceedings of the IEEK Conference
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    • 2004.06a
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    • pp.217-220
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    • 2004
  • This paper presents design simulation, implementation, and measurement of a miniaturized GPS/K-PCS dual-band LTCC chip antenna for mobile communication handsets. The dimension of LTCC chip antenna is $9mm{\times}15mm{\times}1.2mm$. The lower meander type antenna is to be tuned to the lower frequency (GPS) band and the upper meander antenna with via hole connection is to contribute the higher frequency (K-PCS) band. In order to lowering the resonant frequency for GPS band, two printed modified meander antenna with gap stub is used to integrate with PCS band operation. The measured resonant frequency at GPS band shifts to lower frequency about 100MHz. The measured impedance bandwidth(VSWR $\leq$ 2) are 55MHz and 120MHz at the resonant frequency. respectively.

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Effect of Pr substitution on the superconducting properties of (Pb0.5Cd0.5)SrLaCuOz

  • Lee, H.K.
    • Progress in Superconductivity and Cryogenics
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    • v.17 no.3
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    • pp.5-8
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    • 2015
  • The effects of Pr substitution on the structural and the superconducting properties for Pb-based 1201 cuprates with compositions of $(Pb_{0.5-x}Pr_xCd_{0.5})SrLaCuO_z(0{\leq}x{\leq}0.25)$ and $(Pb_{0.45}Pr_{0.05}Cd_{0.5})(Sr_{1-y}La_{1+y})CuO_z(0{\leq}y{\leq}0.1)$ were investigated. It is found that $T_c$ decreases as the Pr-doping content x increases in the $(Pb_{0.5-x}Pr_xCd_{0.5})SrLaCuO_z$ samples, whereas $T_c$ of $(Pb_{0.45}Pr_{0.05}Cd_{0.5})(Sr_{1-y}La_{1+y})CuO_z$ samples increases as the La-doping content y increases. The experimental results were discussed in connection with the change in hole concentration of the samples.

Two Populations in Young Radio Galaxies

  • Woo, Jong-Hak;Son, Dong-Hoon;Kim, Sang-Chul;Park, Dae-Seong;Kawakatu, Nozomu
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.33.1-33.1
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    • 2012
  • We investigate the disk-jet connection of Young Radio Galaxies (YRGs) by comparing emission-line properties with radio luminosity and jet size. By combining new optical spectra for 21 objects with SDSS archival data for 15 objects, we selected a sample of 36 low-redshift YRGs at z < 0.4. We find that YRGs are classified in high- and low-excitation galaxies based on the relative strength of high-to-low excitation line strengths, suggesting that there are two populations in YRGs as similarly found in large radio galaxies, i.e., FRIs and FRIIs. High-excitation galaxies (HEGs) have higher emission line luminosities than low-excitation galaxies (LEGs) at fixed black hole mass and radio luminosity, suggesting that the Eddington ratio is higher in HEGs than in LEGs and that for given radio activity HEGs have higher accretion activity than LEGs. The difference between HEGs and LEGs is probably due to either mass accretion rate or radiative efficiency.

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Effects of Cd substitution on the superconducting properties of (Pb0.5Cu0.5-xCdx)Sr2(Ca0.7Y0.3)Cu2Oz

  • Lee, Ho Keun;Kim, Jin
    • Progress in Superconductivity and Cryogenics
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    • v.20 no.2
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    • pp.24-28
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    • 2018
  • To understand the effects of Cd substitution for Cu, $(Pb_{0.5}Cu_{0.5-x}Cd_x)Sr_2(Ca_{0.7}Y_{0.3})Cu_2O_z$ (x = 0 ~ 0.5) compounds were synthesized and the structural and superconducting properties of the compounds were characterized. Resistivity data revealed that superconducting transition temperature rises initially up to x = 0.25 and then decreases as the Cd doping content increases. Room-temperature thermoelectric power decreases at first up to x = 0.25 and then increases with higher Cd doping content, indicating that the change in $T_c$ is mainly caused by the change in the hole concentration on the superconducting planes by the Cd doping. The non-monotonic dependence of the lattice parameters and the transition temperature with Cd doping content is discussed in connection with the possible formation of $Pb^{+2}$ ions and the removal of excess oxygen caused by Cd substitution in the charge reservoir layer. A correlation between transition temperature and c/a lattice parameter ratio was observed for the $(Pb_{0.5}Cu_{0.5-x}Cd_x)Sr_2(Ca_{0.7}Y_{0.3})Cu_2O_z$ system.