• Geomechanics and Engineering
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• 제24권5호
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• pp.431-441
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• 2021

Rock-socketed drilled shafts are widely used to transfer the heavy loads from the superstructure especially in mountainous area. Extensive research has been done on the behavior of rock-socketed drilled shafts under compressive load. However, little attention has been paid to uplift behavior of drilled shaft in rock, which govern the overall behavior of the foundation system. In this paper, a series of centrifuge tests have been performed to investigate the uplift response of rock-socketed drilled shafts. The pull-out tests of drilled shafts installed in layered rocks having various strengths were conducted. The load-displacement response, axial load distributions in the shaft and the unit skin friction distribution under pull-out loads were investigated. The effects of the strength of rock socket on the initial stiffness, ultimate capacity and mobilization of friction of the foundation, were also examined. The results indicated that characteristics of rock-socket has a significant influence on the uplift behavior of drilled shaft. Most of the applied uplift load were carried by socketed rock when the drilled shaft was installed in the sand over rock layer, whereas substantial load was carried by both upper and lower rock layers when the drilled shaft was completely socketed into layered rock. The pattern of mobilized shaft friction and point where the maximum unit shaft friction occurred were also found to be affected by the socket condition surrounding the drilled shaft.

• 반도체디스플레이기술학회지
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• 제21권1호
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• pp.148-154
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• 2022

As the 4th industrial age approaches, the demand for semiconductors is increasing enough to be used in all electronic devices. At the same time, semiconductor technology is also developing day by day, leading to ultraprecision and low power consumption. Semiconductors that keep getting smaller generate heat because the energy density increases, and the generated heat changes the shape of the semiconductor package, so it is important to manage. The temperature change is not only self-heating of the semiconductor package, but also heat generated by external damage. If the package is deformed, it is necessary to manage it because functional problems and performance degradation such as damage occur. The package burn in test in the post-process of semiconductor production is a process that tests the durability and function of the package in a high-temperature environment, and heat dissipation performance can be evaluated. In this paper, we intend to review a new material formulation that can improve the performance of the adapter, which is one of the parts of the test socket used in the burn-in test. It was confirmed what characteristics the basic base showed when polyamide, a high-molecular material, and alumina, which had high thermal conductivity, were mixed for each magnification. In this study, functional evaluation was also carried out by injecting an adapter, a part of the test socket, at the same time as the specimen was manufactured. Verification of stiffness such as tensile strength and flexural strength by mixing ratio, performance evaluation such as thermal conductivity, and manufacturing of a dummy device also confirmed warpage. As a result, it was confirmed that the thermal stability was excellent. Through this study, it is thought that it can be used as basic data for the development of materials for burn-in sockets in the future.

• 한국지반공학회논문집
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• 제25권8호
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• pp.5-21
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• 2009

암반에 근입된 현장타설말뚝의 주면마찰력에 대한 최근의 연구결과에 따르면 주면마찰력은 암석의 일축압축강도 외에 굴착면의 거칠기, 암반의 재료특성, 초기 수직음력, 말뚝의 직경, 암반의 절리 및 풍화도 등에 크게 영향을 받는 것으로 보고되어 있다. 지금까지 개발된 굴착면 거칠기 시스템들은 공기 중에서만 측정가능하므로 현장의 굴착공내에서 직접 측정하는 것은 불가능하였다. 따라서, 본 연구에서는 수중에서 사용가능한 굴착공 벽면거칠기 측정 시스템(BKS-LRPS)을 개발하였으며, 특수 제작된 보정장치를 통하여 여러 가지 경우에 대한 검증을 수행하였다. 연구결과에 의하면, 개발된 BKS-LRPS는 장치제작조건 및 현장조건을 반영하도록 계획된 검증조건들에 대하여 유효측정영역을 제시할 수 있었다.

• Journal of Periodontal and Implant Science
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• 제39권sup2호
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• pp.287-291
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• 2009

Purpose: The objective of this clinical presentation was to present a clinical case series report of socket preservation, sinus augmentation, and bone grafting using a horse-derived biomaterial. Methods: A horse-derived biomaterial was used in 8 patients for different indications including socket preservation following tooth extraction, osseous bone grafting, and sinus augementation procedures. Surgeries were performed by a well trained specialist and clinical radiographs were obtained at designated intervals. Biopsy cores of 2 ${\times}$ 8 mm prior to implant placement was obtained following a healing interval of 4 - 6 months. A clinical and histologic evaluation was performed to evaluate the clinical effectiveness and biocompatibility of the biomaterial. Results: All surgeries in 8 patients were successful with uneventful healing except for one case with membrane exposure that eventually resulted with a positive outcome. Radiographic display of the healing phase during different intervals showed increased radiopacity of granular nature as the healing time increased. No signs of adverse effect or infection was observed clinically and the tissues surrounding the biomaterial seemed well-tolerated with good intentional healing. The augmented sinuses healed uneventfully suggesting in part, good biocompatibility of the biomaterial. Dental implants placed following socket preservation were inserted with high initial torque suggesting good initial stability and bone quality. Conclusions: Our results show that at least on a tentative level, a horse-derived biomaterial may be used clinically in socket preservation, sinus augmentation, bone grafting techniques with good intentional healing and positive results.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 추계학술대회 논문집
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• pp.533-534
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• 2008

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.58-61
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• 1998

In this paper, we analyzed SSL(Secure Socket Layer) protocol, symmentric algorithm is borken by choosen attack and known attack. This protocol prevents SSL form reusing a key and make new key without computational load of public-key algorithm.

• 콘크리트학회지
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• 제28권3호
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• pp.40-45
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• 2016

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2002년도 춘계학술대회
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• pp.350-350
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• 2002

치아 외상은 크게 fracture와 luxation injury로 분류된다. 이 중에서 영구치의 root fracture는 외상의 0.5~0.7%를 차지하는 것으로 조사되고 있다. 호발부위로는 상악 중절치가, 나이로는 11~20세에서 호발하여, 이보다 어린 나이에서는 alveolar socket의 elasticity 때문에 fracture보다는 luxation 쪽으로 많이 발생하는 것으로 보고되고 있다.(중략)

• Animal cells and systems
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• 제7권4호
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• pp.331-335
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• 2003

Vertebrates with different habitats have different proportions of visual cells, with the rod cells responding to scotopic vision and the cone cells responding to photopic and color vision in their retinas. The present work studied whether the kinds and arrangement patterns of the cone cells and interlocking morphology of the lens were related to the kind of preys and habitats in the genus Zacco. The retinas were observed by a light microscopy using H-E staining method and the interlocking formula of the lens fibers were investigated by a scanning electron microscopy. The interlocking formula of the lens fibers of Z. temmincki is an ' anchor and socket ' connection, and that of Z. platypus is a ' ball and socket ' connection. The cone cells of Z. platypus and Z. temmincki constituted compacted mosaic patterns of row type. Away from the center, the double and single cone cells gradually increased in diameter. Zacco temmincki had identical double cone cells and Z. platypus had non-identical double and single cone cells. The eyes of Z. temminckifeeding on a moving aquatic insects in relative limpid water and swift current of mid and upper stream have better resolution than that of Z. platypus feeding on mainly adhesive algae and some aquatic insects in slightly turbid water of mid stream.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1587-1590
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• 2005

A rigid-plastic finite element analysis for the die forging process of a socket ball joint, which is used in the transportation system, was carried out. And also with the results, the elastic stress analysis for the forging die was performed in order to get basic data for the die life prediction. The die fatigue life prediction was simulated using Goodman's and Gerber's equation. The prediction technique for the fatigue life of a forged product, the socket ball joint, using DEFORM-3D is presented and the results are commented upon. Archard's wear model was used for the wear simulation and then the wear simulation and then the wear quantity was quantity was evaluated using volume. In order to prove the wear simulation results to be reliable, wear quantity of the real forging die set in used a forging factory was measured using a 3-dimensional measurement apparatus. The simulation results were relatively in good agreement with the experimental measurements.