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Development of Non-Scallop Block Joint Welding Method (논-스캘럽 블록 조인트 용접법 개발)

  • Kim, Ho-Kyeong;Ko, Dae-Eun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.9
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    • pp.5419-5424
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    • 2014
  • A weld scallop is a small quadrant or half circle type hole installed in the weld line cross area for easy welding operation. Many types of T-bars with a scallop can be welded in a block assembly stage in shipbuilding. The difficulties arise from the fact that scallops are to be filled by build-up welding after welding of the cross line is complete. In this study, a non-scallop block joint welding method was developed using special type CBM (ceramic backing material). The wedge shaped CBM was devised to insert a CBM into just the V groove of weld line cross area without weld scallop. A saw-toothed shape was adopted for easy cutting of the unnecessary part in the CBM fitting process. The applicability of the developed method was verified through welding experiments based on the yard welding conditions.

Purification and Characterization of Hrp1, a Homolog of Mouse CHD1 from the Fission Yeast Schizosaccharomyces pombe

  • Yong Hwan Jin;Eung Jae Yoo;Yeun Kyu Jang;Seung Hae Kim;Chee-Gun Lee;Rho Hyun Seong;Seung Hwan Hong;Sang Dai Park
    • Animal cells and systems
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    • v.2 no.4
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    • pp.539-543
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    • 1998
  • Hrp1, of Schizosaccharomyces pombe, is a new member of the SW12/SNF2 protein family that contains a chromodomain and a DNA binding domain as well as ATPase/7 helicase domains. This configuration suggests that Hrp1 could be a homolog of mouse CHD1, which is thought to function in altering the chromatin structure to facilitate gene expression. To understand the enzymatic nature of Hrp1 we purified the 6-Histidine-tagged Hrp1 protein (6$\times$His-Hrp1) to homogeneity from a S. pombe Hrp1-overexpressing strain and hen examined its biochemical properties. We demonstrate that the purified 6$\times$His-Hrp1 protein exhibited a DNA-binding activity with a moderate preference to the (A+T)-rich tract in double-stranded NA via a minor groove interaction. However, we failed to detect any intrinsic DNA helicase activity from the purified Hrp1 like other SW12/SNF2 proteins. These observations suggest that the DNA binding activities of Hrp1 may be involved in the remodeling of the chromatin structure with DNA-dependent ATPase. We propose that Hrp1 may function in heterochromatins as other proteins with a chromo- or ATPase/helicase domain and play an important role in the determination of chromatin architecture.

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Comparison and Estimation of Fretting Fatigue Damage Parameters for Aluminum Alloy A7075-T6 (A7075-T6 알루미늄 합금의 프레팅 피로 손상 파라미터 비교 평가)

  • Hwang, Dong-Hyeon;Cho, Sung-San
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.10
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    • pp.1229-1235
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    • 2011
  • Fatigue tests were conducted on the aluminum alloy, A7075-T6 to determine the most reliable fretting fatigue damage parameter. Specimens with grooves were used, so that either fretting fatigue crack at the pad/specimen interface or plain fatigue crack at the groove could be nucleated, depending on the pad pressure. Both the crack nucleation location and initial crack orientation were examined using optical microscopy, and the results were used to assess the reliability of the various fretting fatigue damage parameters that have been most commonly used in the literature. Finite element analysis was employed to obtain the stress and strain data of the specimen, which were needed to estimate the parameter values and the orientation of the critical plane. It was revealed that both the Fatemi.Socie and McDiarmid parameters, which assume shear-mode fatigue cracking, are the most reliable.

Fracture Resistance and Stress Distribution of All Ceramic Crowns with Two Types of Finish Line on Maxillary First Premolar (상악 제1소구치에서 전부도재관의 finish line 형태에 따른 파절강도와 응력 분포에 관한 연구)

  • Lee, Sang-Kwon;Dong, Jin-Keun
    • Journal of Dental Rehabilitation and Applied Science
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    • v.19 no.3
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    • pp.219-237
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    • 2003
  • he purpose of this study was to compare the fracture resistance of the IPS Empress ceramic crown with 1.0mm width rounded shoulder, which is usually recommended in all ceramic crown, and 0.5mm width chamfer finish lines on the maxillary first premolar. 30 sound maxillary first premolars were selected and then storaged in 5% NaOCl and saline. 15 teeth were performed preparation for each group(1.0mm rounded shoulder, 0.5mm chamfer). After 30 stone dies were made for each group, the IPS Empress ceramic crowns were fabricated and cemented with resin cement(Bistite resin cement, Tokuyama Soda Co. LTD., Japan) on the natural teeth. The cemented crowns were mounted on the positioning jig and the universal testing machine(Zwick Z020, Zwick Co., Germany)was used to measure the fracture strength, with stress loading on the occlusal surface between buccal and lingual cusp. And also, three-dimensional finite element model was used to measure the stress distribution with two types of the finish lines(1.0mm rounded shoulder, 0.5mm chamfer) and two loading conditions(both buccal and lingual cusp inclination, lingual cusp inclination only). The result of the this study were as follows. In the fracture resistance experiment according to the finish line, the mean fracture strength of rounded shoulder(842N) showed higher value than that of the chamfer(590N) (p<0.05). In the three dimensional finite element analysis of all ceramic crown, metal die and natural teeth model did not show any differences in stress distribution between finish lines. Generally, when force was loaded on the occlusal inclination of buccal and lingual cusp, the stress was concentrated on the loading point and the central groove of occlusal surface. When force was loaded only on the occlusal inclination of lingual cusp, the stress was concentrated on the lingual finish line and loading point.

The Effect of Curvature Radius and Material of Diaphragm on the Valve Opening Time in Diaphragm Type S/R Valve (S/R 밸브에서 격막의 곡률반경과 재료가 밸브 개구시간에 미치는 영향)

  • Cheon, Heung-Kyun;Hwang, Jae-Gun;Cho, Tae-Seok;Kwon, Young-Doo;Kwon, Soon-Bum
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.2961-2966
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    • 2007
  • When the pressure at the weak spot established at a certain part of a high pressure vessel or piping system exceeds a design pressure, this weak spot is burst, and the pressurized gas emitted through the weak spot will cause a compression wave system. In this connection, in the present study, an experimental study by using a conventional shock tube facility is performed to estimate the effects of the material of diaphragm, curvature radius and thickness of materials on the valve opening time in diaphragm. Pressure sensor having 500kHz in natural frequency is installed at 35mm downstream of the rupture diaphragm to measure the static pressure history of propagating and being accumulated compression wave. 4 kinds of materials are used as diaphragm that is aluminium, copper, stainless steel and zinc. The diaphragm radii of curvature R are ${\infty}$, 120mm and 60, respectively. And the depth for $90^{\circ}$ groove is 0.04mm. It is found that the smaller the tensile strength and elongation of the rupture diaphragm is, the smaller the radius of curvature of the rupture diaphragm is, and for the same conditions the thinner the thickness of the rupture diaphragm is, the shorter the valve opening time becomes. Also, the tensile strength, elongation and the radius of curvature of the rupture diaphragm for the same conditions are smaller, the maximum pressure rise caused by the coalescences of the compression wave is smaller. Finally the pressure ratio is higher, the valve opening time is shortened and gradient of pressure increment is more steepen.

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A Study on the Micro-Formability of Al 5083 Superplastic Alloy Using Micro-Forging System (마이크로 단조 시스템을 이용한 Al 5083 초소성 합금의 마이크로 성형성에 관한 연구)

  • Son S. C.;Kang S. G.;Park K. Y.;Na Y. S.;Lee J. H.
    • Transactions of Materials Processing
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    • v.14 no.5 s.77
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    • pp.432-438
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    • 2005
  • Among the most of manufacturing process, plastic deformation method offers a significant advantage in productivity and enable mass production with controlled quality and low cost. From the point of view, micro forming is a well suited technology in manufacturing very small metallic parts, in particular for mass production, as they are required in many industrial products. Meanwhile, Al 5083 superplastic alloy with very small grains has a great advantage in achieving micro deformation under low stress due to its relatively low strength at a specific high temperature range. This paper describes the micro formability of Al 5083 superplastic alloy and its application to die forging of micro patterns. Micro formability tests of Al 5083 superplastic alloy were carried out with the specially designed micro forging system by using V-grooved micro dies and pyramidal dies made of (100) silicon. With these dies, micro forging was conducted by varying the applied load, material temperature and forging time The micro formability of Al 5083 superplastic alloy was evaluated by comparing $R_f$ value, where $R_f\;=\;A_f/A_v$ ($A_v$ : cross-sectional area of the flowed metal, $A_v$ : cross sectional area of V-groove). The micro formability of 3 dimensional Patterns was also evaluated using Pyramidal type micro dies.

Black Body Design and Verification for Non-Uniformity Correction of Imaging Sensor and Uncertainty Analysis (영상센서의 비균일 응답특성 보정을 위한 흑체 설계 및 성능검증과 보정오차 분석)

  • Shin, Somin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.3
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    • pp.240-245
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    • 2013
  • Each pixel of InfraRed(IR) sensor differently responds to IR light as time elapses or the sensor on/off operation is repeated. As a result, the quality of IR sensor image is deteriorated, and therefore NUC(Non-uniformity Correction) is periodically needed for IR sensor. In this paper, in order to perform NUC in the Satellite, on-board V-grooved blackbody is designed with a baffle so that the emissivity of black body is to be higher than 0.995 as well as the temperature deviation is less than $1^{\circ}C$ in the range of the infrared wave length from 3.3 to $5.2{\mu}m$. To check its performance, the emissivity and the surface temperature of the blackbody by TRT(Transfer Reference Thermometer) and IR Micrometer scanner are measured, respectively. From the results, black body design is verified and the uncertainty of NUC is estimated through the measurement results.

The Effects of High Pressure Water Contact State on Hydraulic Fracturing (고압수 접촉상태가 수압파쇄에 미치는 영향)

  • Lee, Sang Hun;Lim, Jong Se;Jang, Won Yil
    • Tunnel and Underground Space
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    • v.26 no.5
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    • pp.409-417
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    • 2016
  • The shale gas is emerging as one of the oil and gas resources which can replace the traditional oil and gas resources. As the shale layer where the shale gas is deposited has low permeability, the hydrofracturing method is required to improve the productivity. This study is designed to conduct the laboratory hydrofracturing test on the samples which are modeled after the drilling hole having the general drilling hole and spiral groove. And compare the initial fracturing pressure and fluid contact between them in order to the result of the hydrofracturing depending on the shape of the drilling hole. In addition, the results were compared with the numerical modeling values from 3DEC and they were also compared with the data from the advance researches. It was found from the study that rather than the contact area of the high pressures water, the force concentration depending on the form of guide hole was more effective in the hydrofracturing.

The Alar Extension Graft for Retracted Ala (Alar Extension Graft를 이용한 콧방울뒤당김의 교정)

  • Kim, Hyun soo;Roh, Si Gyun
    • Archives of Plastic Surgery
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    • v.36 no.1
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    • pp.66-74
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    • 2009
  • Purpose: The importance of the deformities in alar - columellar complex has been underestimated in Asian ethnic groups for the last decades. Fortunately, with increasing familiarity of the open rhinoplasty techniques, the anatomic details of the nasal tip have been pointed up. Definitely, having an interest and demand for improving the sub - normal relationship between the alar rim and columella are indebted for such growing of knowledge about nasal tip anatomy. However, it is true that any single procedure is not settled as versatile and fully confident modality to correct the retracted notching of the alar rim. With this article, I should like to propose another useful option for treating retracted ala. Methods: The author has tried to correct alar rim retraction by means of: (1) Triangular onlay septal cartilage graft on the lower lateral cartilage with the medial end fixed to the anterior surface of the lateral crus(Alar extension graft), (2) Inserting lateral end of the alar extension graft to the vestibular skin pocket in the form of a finger - in - groove, (3) using the vestibular skin in the form of an advancement flap, and (4) using the soft shield graft to prevent possible visible step - off of the alar margin. Results: The author applied an alar extension graft to 16 patients in order to correct a retracted ala for the last 27 months (August, 2003 - October, 2005). The distances from alar rim to long axis of nostril were improved to be within 2 mm in all of the cases, and also the shape of the alar rim changed to a round form. Nostril asymmetry (6%) in one case, temporary palpable step - off (18%) in three cases, temporary visible step - off (6%) in one case, and temporary paresthesia of the tip (25%) in four cases were observed. Conclusion: The alar extension graft is simple and efficacious. It does not need donor sites other than the operative field, and its results are predictable. In particular, since it may give structural intensity to a weak lower lateral cartilage, it may be preferentially used for the correction of a retracted ala that arises from hypoplastic lower lateral cartilage. Moreover intensified lower lateral cartilage also improves the esthetic shape of lobule.

A Study of Proprioceptive Neuromuscular Facilitation Principles (고유수용성 신경근 촉진법 원리에 관한 고찰)

  • Bae Sung-Soo
    • The Journal of Korean Physical Therapy
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    • v.5 no.1
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    • pp.109-114
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    • 1993
  • The originator of the proprioceptive neuromuscular facilitation method was Dr. Herman Kabat, a man who received the bachelor of science degree from New York University in 1932. In 1936 he moved to the University of Minnesota where he served as instructor in physiology and also studies medicine. He received his medical doctorate in 1942. When Dr. Karbat meet Sister Kenny suggested that certain change. She does not receptive his ideas. So that he decided to pursure the treatment of patients. Upon the establishment of the Karbat- kaiser Institute to be opened in 1946. Margaret Knott, the first physical therapist to be employed by him and to become his head physical therapist. In 1948 Vallejo center was opened. Dr. Kabat developed the PNF method combined motions to ascertain the effectiveness of maximal resistance and stretch in facilitating the response of a weak distal muscle. He identified mass movement patterns that were spiral and diagonal in character in 1965. Margaret Knott presented lecture at tile APTA Annual Conference in Las Vegas. The title was In the groove. On December 18, 1978 she passed away at her home in Vallejo. Marie-Louise Mangold is director of the Kaiser Foundation Rehabilitation Center now. She is the Vice President of International Proprioceptive Neuromuscular facilitation Association. About 20 physical therapist working teaching and study at KFRC in Vallejo. PNF neuromuscular mechanism becomes integrated and efficient without awareness of individual muscle action, reflex and a multitude of other neurophysiological reactions. The principles of PNF are visual consideration, verbal consideration, and proprioceptive input consideration with tactile stimulation, joint receptors, appropriate facilitation, stretch reflex normal timing, irradiation, pattern of movement.

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