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A Stydy on Steel Wire Fiber Reinforced Refractory Castable (철근 캐스터블 내화물의 고온특성에 관한 연구)

  • 박금철;최영섭;한문희;장영재;박근원
    • Journal of the Korean Ceramic Society
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    • v.17 no.2
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    • pp.69-74
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    • 1980
  • This study deals with the wire content, wire diameter, aspect ratio , it's arrangement of steel, wire fiber and the sorts of castable which affected the character of steel wire fiber reinformced refractory castable. Two kinds of alumina based refractory castables, one is for 1650℃ and the other is for 1800℃, and stainless steel which is SUS 304 type 0.25, 0.34 , 0.37 and 0.50m/min diameter were used respectively. Aspect ratio was adjusted to 50, 75, 100 and steel fiber content was also adjusted to 1-4wt% each. The results of the experiment were as follows : 1. At firing temperature around 1,000℃, MOR is increased with increasing wire content and aspect ratio with decreasing firing temperature, which depends on the Romualdi's Fiber Spacing Theory. But for calculation of the fiber spacing, Swamy equation is more a aplicable to the extensive fiber mixing conditions. However, the condition differs from the above at firing temperature around 1,350℃ ,because of the degradation of wire and the progress of sintering of castable. 2. Linear change is getting larger corresponding to the increase of wire content, and the spaling resistivity is increasing corresponding to the increase of wire content and to aspect ratio, and with decreasing wire diameter. 3. Firing shrinkage under load is getting greater as higher wire content, and the shrinkage of the test pieces which fiber is vertically oriented is getting greater than the test pieces which fiber is randomly oriented.

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A COMPARATIVE STUDY OF FRICTIONAL RESISTANCES BETWEEN ORTHODONTIC BRACKETS AND ARCH WIRE DURING SLIDING MOVEMENT OF TEETH (치아의 활주 이동시 교정용 brackets와 arch wire사이에서 발생하는 마찰 저항력에 관한 비교 연구)

  • Min, Jung-Mi;Suhr, Cheong-Hoon
    • The korean journal of orthodontics
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    • v.18 no.1 s.25
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    • pp.155-163
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    • 1988
  • The purpose of this study was to evaluate and compare frictional forces generated between orthodontic brackets and arch wires. Independent variables were chosen for study: arch wire size and shape, arch wire material, bracket width, and second-order angulation between bracket and arch wire. Kinetic frictional forces of stainless steel (0.014', 0.016', 0.018', 0.016' ${\times}$ 0.022', 0.018' ${\times}$ 0.022'), $\beta-titanium$ (0.016' ${\times}}$ 0.022') arch wires were measured on wide and junior edgewise twin brackets (0.018' ${\times}$ 0.022' slot). Instron was used to pull arch wires while $0^{\circ},\;3^{\circ},\;6^{\circ},\;or\;9^{\circ}$ angulation between and wire and bracket was given. The results were as follows: 1. The frictional force of $\beta-titanium$ wire was larger than that of stainless steel wire. 2. The frictional force was generally increased as the size of wire is increased. 3. The frictional force of rectangular wire was larger than that of round wire. 4. As second order angulation was increased, the frictional force was also increased. 5. The frictional force was larger on a wide bracket than on a junior bracket.

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Implementation of Electro-Mechanical Brake(EMB) for Brake-By-Wire System of Electric Vehicle (전기 자동차용 Brake-By-Wire 시스템을 위한 전자식 브레이크 구현)

  • Ryu, Hye-Yeon;Jeong, Ki-Min;Kim, Man-Ho;Lee, Kyung-Chang
    • Journal of the Korean Society of Industry Convergence
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    • v.20 no.4
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    • pp.313-323
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    • 2017
  • As vehicles become more intelligent this is focused on ways to enhance safety and convenience for both drivers and passengers. In particular, x-by-wire systems that replace rigid mechanical components with dynamically configurable electronic elements are being developed to expand intelligent functions, such as adaptive cruise control or lane departure warning system. Because the malfunction of safety-related modules controlling critical functions, such as brakes, throttle, and steering in x-by-wire systems, can cause injury or death, safety and reliability are the most critical issue for automotive vendors and parts manufacturers. In an effort to develop better and effective brake-by-wire system, this paper presents EMB system by using the low speed electric vehicle, which is not required large braking force, with motor controller. In addition, we design performance evaluation system of EMB with 1/4 low speed electric vehicle model and suggested EMB is evaluated through the performance evaluation system.

Flow Boiling Heat Transfer Characteristics of Liquid Nitrogen in Plain and Wire Coil Inserted Tubes (평활관 및 와이어코일을 삽입한 열전달촉진관에서 액체질소의 흐름비등열전달 특성)

  • Hwang Jee-Sang;Yun Rin;Kim Yongchan;Chung Jin Taek
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.29 no.8 s.239
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    • pp.927-933
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    • 2005
  • Boiling heat transfer characteristics of liquid nitrogen in a stainless steel plain tube and wire coil inserted tubes were investigated. The test tubes, which had an inner diameter of 10.6 m and a length of 1.65 m, were horizontally located. Five wire coils having different pitch and thickness were inserted into the plain tube. The pitches of the wire coils were 18.4, 27.6, and 36.8 m, and the thickness was 1.5, 2.0, and 2.5 mm respectively. Tests were conducted at a saturation temperature of $-191^{\circ}$, mass fluxes from 58 to 105 kg/$m^2s$, and heat fluxes from 22.5 to 32.7 kw/$m^2$. A direct heating method was used to apply heat to the test section. The boiling heat transfer coefficients of liquid nitrogen were represented as a function of vapor quality, which showed significant drop at the dryout vapor quality. The maximum heat transfer enhancement using the wire coil inserted tubes over the plain tube was $174\%$ for 'Wire 3' having a thickness of 2.5 mm and a pitch of 18.4 mm.

Development of Digital Fault Detection Systems for Screening Open and Short of Wire Harness (와이어 하네스 단선 단락 선별을 위한 디지털 고장 검출 시스템 개발)

  • A Ran Kim;Jae Wan Park;Ha Seon Kim;Jae Hoon Jeong;Sun Young Kim
    • Journal of Drive and Control
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    • v.20 no.4
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    • pp.140-149
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    • 2023
  • Wire harness is a component for efficient control when electronic parts are required such as construction machinery and electric vehicles. With emerging issues such as autonomous driving and automation in construction, a wire harness composed of multiple cables has become an essential part because more electronic parts are required. However, when a wire harness failure occurs, systems can be stopped, accidents can occur, and economic damage can be significant. Therefore, in this paper, we developed a digital fault screening system that could easily and quickly diagnose faults in the wire harness. The principle of the developed system was to sequentially send pulse signals to the wire harness and use returned signals to perform fault detection. As a result of diagnosing faults using the developed failure detection system, a detection accuracy of 99.9 % was confirmed through the experiments.

A Study on the Electrical Characteristics of Different Wire Materials

  • Jeong, Chi-Hyeon;Ahn, Billy;Ray, Coronado;Kai, Liu;Hlaing, Ma Phoo Pwint;Park, Susan;Kim, Gwang
    • Journal of the Microelectronics and Packaging Society
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    • v.20 no.4
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    • pp.47-52
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    • 2013
  • Gold wire has long been used as a proven method of connecting a silicon die to a substrate in wide variety of package types, delivering high yield and productivity. However, with the high price of gold, the semiconductor packaging industry has been implementing an alternate wire material. These materials may include silver (Ag) or copper (Cu) alloys as an alternative to save material cost and maintain electrical performance. This paper will analyze and compare the electrical characteristics of several wire types. For the study, typical 0.6 mil, 0.8 mil and 1.0 mil diameter wires were selected from various alloy types (2N gold, Palladium (Pd) coated/doped copper, 88% and 96% silver) as well as respective pure metallic wires for comparison. Each wire model was validated by comparing it to electromagnetic simulation results and measurement data. Measurements from the implemented test boards were done using a vector network analyzer (VNA) and probe station setup. The test board layout consisted of three parts: 1. Analysis of the diameter, length and material characteristic of each wire; 2. Comparison between a microstrip line and the wire to microstrip line transition; and 3. Analysis of the wire's cross-talk. These areas will be discussed in detail along with all the extracted results from each type the wire.

Effect of Toughness Index of Diamond Abrasives on Cutting Performance in Wire Sawing Process (와이어쏘 공정에서 다이아몬드 입자의 인성지수가 절단 성능에 미치는 영향)

  • Kim, Do-Yeon;Lee, Tae-Kyung;Kim, Hyoung-Jae
    • Journal of the Korean Society of Industry Convergence
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    • v.23 no.4_2
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    • pp.675-682
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    • 2020
  • Multi-wire sawing is the prominent technology employed to cut hard material ingots into wafers. This paper aimed to research the effect of diamond toughness index on the cutting performance of electroplated diamond wire. Three different toughness index of diamond abrasives were used to manufacture electroplated diamond wires. The cutting performance of electroplated diamond wire is verified through experiments, in which sapphire ingot are cut using single wire sawing machine. A single wire saw for constant load slicing is developed for the cutting performance evaluation of electroplated diamond wire. Choosing the cutting depth, total cutting depth, cutting force and wear of electroplated diamond wires as evaluation parameters, the performance of electroplated diamond wire is evaluated. The results of this study showed that there was a significant direct relationship between the toughness index of diamond abrasives and the cutting performance. Results demonstrated that diamond abrasive with a high toughness index showed higher cutting performance. However, all diamond abrasives showed similar cutting performance under low load conditions. The results of this paper are useful for the development of cutting large diameter ingots and cutting high hardness ingots at high speed.

Gear Train Development for CNC Wire Bending Machine (CNC 와이어 벤딩기 구동장치 개발)

  • Cho, Hyun-Deog;Choi, Sung-Jong
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.7 no.4
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    • pp.50-55
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    • 2008
  • CNC wire bending machines are used in industries to make a type variety of wire products such as long links. The machines have a long arm device to rotate in order to remove forming errors by flexibility of wire. Generally, the machines which constructed servo motors in the arm have the rotating range of the arm under 360 degree because the servo motors connect with fixed control devices on frame by many cables. The rotating angle under 360 degree limits working speed and forming geometry. Therefore this study developed a gear train to drive a parts in arm and to be independent on arm rotation movement. The developed gear train can transfer four movements to four components in arm and is consists parallel of four pairs of satellite gear trains. This study constructed the CNC wire bending machine with the developed gear train and verified that the gear train could drive internal components independently on arm rotation.

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FRICTIONAL FORCES BETWEEN ORTHODONTIC WIRE AND BRACKET UNDER ARTIFICIAL SALIVA (인공타액하에서 교정선과 Bracket간의 마찰력에 대한 연구)

  • Ko, Jeong-Seok;Yang, Kyu-Ho
    • The korean journal of orthodontics
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    • v.18 no.1 s.25
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    • pp.55-63
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    • 1988
  • It has been suggested that the frictional force between bracket and arch wire may impede the tooth movement. The present study was aimed to compare and analyze the effect of wire size, type of ligation, and duration of ligation on the magnitude of frictional force between cobalt chromium wire and stainless steel bracket under the artificial saliva. The results were as follows: 1. Type of ligation and size of wire were the main influencing factor on the level of friction. 2. Stainless steel ligature generated higher frictional forces than elastomeric module. 3. The rectangular wire consistently exhibited more frictional force values than round wires, while there was no significant difference between frictional forces of round wires. 4. In elastic ligature, frictional force decreased with time. 5. Artificial saliva had no significant influence on the frictional force between cobalt chromium wire and bracket.

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Evaluation of Replace period and Useful lifetime of the wire ropes for the Passenger's Elevator (승객용 엘리베이터 와이어로프의 유효수명 및 교체시기 평가)

  • Son, Doo-Ik;Park, Jae-Suk;Oh, Hwan-Seop
    • Journal of the Korean Society of Safety
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    • v.18 no.4
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    • pp.35-38
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    • 2003
  • The wire rope, one of the component of the elevator, is extremely important for the sage operation of the elevator. That is why the wire rope is replaced at a specific interval regradless of the operating conditions or the degree of damage to prevent the breakage of the wire rope. This is the waste of resources, causing economic and environmental loss. This paper has surveyed and analyzed and analyzed the status of replacing wire-rope by buildings that use elevators, in order to compare the replacement cycles of the wire rope under each operating conditions.