• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 추계학술대회 논문집
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• pp.293-294
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• 2008

• Tribology and Lubricants
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• 제25권2호
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• pp.96-101
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• 2009

In order to improve leakage characteristic, angled-circumferential-groove pump seal is suggested. CFD analysis using FLUENT has been performed to predict leakage and determine an optimum slanted-groove angle $\alpha$ which yields the best leakage reduction. The optimum value of $\alpha$ ranges from $45^{\circ}$ to $60^{\circ}$ and depends on the pressure difference of seal and number of grooves for the same groove geometry. The maximum leakage reduction ratio increases as increasing the pressure difference of angled-circumferential-groove pump seal with the optimum value of $\alpha$.

• Journal of Welding and Joining
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• 제33권1호
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• pp.87-93
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• 2015

This study was performed to develop repair technology for J-Groove dissimilar metal weld of pressurizer heater sleeve in nuclear power plants. Pad, J-Groove automatic welding and mechanical machining equipments to develop repair technology using 'Half Nozzle Repair' were designed and manufactured. To obtain the optimum welding process parameters during Pad temperbead overlay welding, several welding experiments using Taguchi method were conducted. Weldability of Pad overlay weld specimens was estimated by PT/RT test, FE-SEM, EDS and Vickers hardness test. Also, J-Groove welding to adjust weld shape conditions requiring in ASME Code was carried out and its integrity of weld specimens was evaluated through PT/RT test and optical microscope. Consequently, it was revealed that Pad and J-Groove overlay welding for dissimilar metal weld of pressurizer heater sleeve could be possible to meet Code standard without weld defect.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2203-2208
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• 2007

Three possible binding modes of cationic meso-tetrakis(N-methylpyridinium-4-yl)porphyrin (TMPyP) to d[(GCATATATGC)2] duplex were investigated by the molecular dynamics (MD) simulation. Among the three binding modes namely, “along the groove”, “across the groove” and “face on the groove”, the “across the groove” model exhibited the largest negative binding free energy and the DNA backbone remained as the B form. In this model, the molecular plain of the TMPyP tilts 45o with respect to the DNA helix axis and is largely exposed to the solvent. TMPyP was stabilized mainly by the interaction between the positively charged neighboring pyridinium moieties of TMPyP and negatively charged phosphate groups of DNA. The result obtained in this work by MD and the report (Jin, B. et al., J. Am. Chem. Soc. 2005, 127, 2417.) that the spectral properties of poly[d(A-T)2] bound TMPyP in the presence and absence of the minor groove binding drug 4',6- diamidino-2-phenylindole are similar, we propose that TMPyP bind across the minor groove of the AT rich- DNA.

• 대한치과보철학회지
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• 제30권4호
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• pp.508-525
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• 1992

The purpose of this study was to evaluate the effect of some resistance form designs on the bond strength of resin-retained prosthesis. Six sub-groups are designed in natural teeth group and resin teeth group . The framework designs in natural teeth group: 1) no groove preparation 2) groove at the center of distal surface 3) groove at the distobuccal line angle 4) 45 degree lateral load with no groove 5) 45 degree lateral load with center groove 6) splint two teeth with no groove. The framework designs in resin teeth group: 1) no groove preparation 2) groove at the center of distal surface 3) groove at the distobuccal line angle 4) metal covered the 1/2 of distal surface 5) metal covered the 1/2 of mesial surface 6) metal extended over the 114 of buccal surface. Specimens were treated electrolytic etching by Oxy-Etch and cemented with Panavia EX. Failure load was measured by Instron. Another 30 specimens were carried out fatigue tests by MTS 810 fatigue testing machine for 5000 cycles at different load level. The following results were obtained from this study. 1. The failure load was significantly increased by resistance forms. 2. The failure load was not increased by increase of total surface area bonded with teeth. The distal surface area played an important role in failure load. 3. In 45 degree lateral load group, the failure load was decreased significantly than that of in vertical load group. 4. Bond failure modes between static test and fatigue test exhibited no differences.

• Journal of Welding and Joining
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• 제22권6호
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• pp.57-63
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• 2004

Fracture toughness is an important parameter in designing offshore structures to ensure resistance to fracture at various temperatures. In this study, a series of experiments is carried out to obtain fracture toughness values (CTOD) of API 2W Gr.50B, welded using FCAW(Flux Cored Arc Weld). In particular, a comparison of absorbed impact energy and CTOD values are made with respect to two different welding groove shapes; double-V-groove and double-bevel-groove. Charpy impact tests are performed for specimens sampled near the root gap, and CTOD tests are carried out for three point bending specimens having the notch at weld zone. While Charpy impact test result is determined to be a good qualitative measure of fracture toughness, no quantitative correspondence between impact absorbed energy and CTOD values was found. Based on the experiment, it is observed that double-V-groove welds give lower transition temperature than those of double-bevel-groove.

• 디지털융복합연구
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• 제16권9호
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• pp.293-299
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• 2018

Led Zeppelin, Steely dan, 밴드 TOTO, Spyro Gyra 등 많은 뮤지션들 사이에서 사랑받아 온 리듬인 Halftime Shuffle Groove에 대해 연구해 본다. 기본적인 Halftime Shuffle의 이해를 토대로 하여 위 뮤지션들의 연주사례들을 기반으로 각 대표 곡들을 비교 분석하여 리듬패턴간의 간결하면서도 상당히 다른 연주방법을 악보, 웨이브 음원 등을 통해 살펴본다. 결과적으로 다양한 가능성들을 살펴 볼 수 있었으며, 세계적으로 인정받은 연주자들의 리듬을 분석하고 연구하여 현대 음악에 좀 더 효율적이고 모던한 리듬패턴의 다양성을 모색해 보는 것은 대단히 중요하다 생각한다. 본 논문은 Halftime Shuffle Groove와 그 성질을 지닌 리듬들을 분석하여 기계화 된 리듬에 편협하지 않는 다양한 가능성에 대해 연구해보는 논문이다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.715-718
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• 2004

In this paper, we studied the characteristics of new polishing pad, which can apply W-CMP process for global planarization of multi-level interconnection structure. The hardness and density were measured as a function of groove pattern. Also, we compared the pore size through the SEM photograph. Finally, we investigated the CMP characteristics with five different kind of groove pattern sample. Through the above results, we can select optimum groove pattern, so we can expect to begin home product of polishing pad.

• Journal of Mechanical Science and Technology
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• 제14권7호
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• pp.737-743
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• 2000

This paper presents the effects of circumferential groove on the minimum oil film thickness in engine bearings. The fluid film pressures are calculated by using the infinitely short bearing theory for the convenience of analysis. Journal locus analysis is performed by using the mobility method. A comparison of minimum oil film thickness of grooved and ungrooved bearing is presented. It is found that circumferential $360^{\circ}$ groove only reduces the absolute magnitude of the oil film thickness, but $180^{\circ}$ half groove affects the shape of film thickness curve and position of minimum oil film thickness.

• 한국기계가공학회지
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• 제19권7호
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• pp.81-88
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• 2020

The geometry and the defect of the groove of the part provoke a sudden change of stress in a local region. The objective of this paper is to investigate the effects of the geometry and the imperfection of a small groove on stress distributions in the vicinity of the joined region for the ABS part with a thin wall using a three-dimensional finite element analysis (FEA). Several types of groove are designed to improve joining characteristics in the vicinity joined region. The imperfection model of the small-sized groove is obtained from observation of deposition characteristics of a fused deposition modeling process. Local stress distributions in the vicinity of the joined region are predicted by the FE model with refined meshes. The influence of the angle and the imperfection of the groove on appearance regions of the maximum stress and distributions of the defined principal stress for different loading conditions is examined using the results of FEAs. Finally, a proper design of the groove is proposed to improve joining characteristics between the substrate and the ABS part.