• 한국경영과학회지
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• 제38권3호
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• pp.87-101
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• 2013

The purpose of this paper is to analyze supplier's optimal decision of the buyback price facing irrational retailers. It has been known that retailers show irrational ordering behaviors, such as pull-to-center effect. We model the retailer's pull-to-center behavior and derive the supplier's optimal buyback price considering the retailer's bounded rationality. The result shows that the supplier's profit can be significantly improved exploiting the retailer's irrationality in the ordering behavior.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.1114-1119
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• 2010

Pile foundations have been used for upholding superstructure's loads. The researches on pile foundations subjected to compressive forces or horizontal loads have been actively carried out. However, recently, pile foundations, which are subjected to pull-out forces, are getting increased. The study on the pull-out resistance of piles becomes to be important. In addition, it is expected that belled piles will be used more and more, since the belled piles are effective to resist the pull-out forces. But there is still a lack of research on pull-out resistance of belled piles. Therefore, in order to investigate the resisting effect against pull-out of belled piles which is embedded in cohesionless soil. a series of pull-out test is performed on belled piles in field. Especially, the relation between load and displacement is analyzed through the pull-out test.

• 대한치과교정학회지
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• 제14권1호
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• pp.75-92
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• 1984

This study attempted to analyze the distribution of stress, to examine the bending effect in the mandible according to the pulling directions and determine on which pulling directions are adequate when an orthopedic force was applied to the mandible. An orthopedic force, 500gm, was applied to the gnathion, one point of the chin area, in three directions. The three directions were ; high puli' from gnathion to the center of condyle head, and vertical pull, from gnathion to a parallel line with the posterior border of the ramus, and medium pull, from the gnathion to a parallel line with the lower border of mandible. The distribution of principal stress, bending moment and amount of displacement within the mandible was analyzed by a 3-dimensional finite element method and that of the various portions of mandible were computed and compared according to the pulling directions. The results were as follows : 1. The bending moment of each part of a mandible has been found to be markedly larger in case of vertical pull than in case of either high pull or medium pull. In vertical pull the bending moment turned out to largest at the condyle head and neck portion, the gonial angle portion, the coronoid portion and the ascending ramus portion, respectively, while comparatively large at the cuspid and bicuspid portion and the first molar portion. In case of high pull it was largest at the gonial angle portion and becoming smaller at the coronoid portion, the ascending ramus portion, the condyle head and neck portion, and the cuspid and bicuspid portion, in that order. In case of medium pull, however, the bending moment was largest at the condyle head and neck portion, becoming smaller at the first molar portion, the ascending ramus portion, the coronoid portion, the cuspid and bicuspid portion, and gonial angle portion, in that order. 2. As for the bending effect it was calculated to be mostly oriented downward at the mandibular body and backward at the mandibular ramus in both high pull and vertical pull. In case of medium pull it was oriented upward at the mandibular body and forward at the mandibular ramus. 3. The bending effect also turned out to be mostly oriented outward in case of high pull and medium pull, and inward in vertical pull. 4. At the mandibular body and ramus, the bending effect in the upward-downward direction and that in the forward-backward direction were found to be larger than in the inward-outward direction. 5. If and when we expect any correcting effect on the mandibular protrusion by means of the chin cup appliance, we can say sure as conclusion that high pull and vertical pull are more effective than medium pull.

• 한국표면공학회지
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• 제34권2호
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• pp.142-150
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• 2001

Due to naturally formed copper oxides, the adhesion strength between copper and epoxy resin is often very poor. To improve the adhesion strength between copper and epoxy resin, Cu-based leadframe sheets were oxidized in a brown-oxide forming solution. Then the effect of brown-oxide formation on the adhesion strength of leadframe to epoxy molding compound (EMC) was studied using pull-out specimens. After the pull-out test, fracture surfaces were analyzed using SEM, AES and EDS to determine failure path. The results showed that the failure path lay over inside the CuO and inside the EMC irrespective of the pull strength.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 춘계학술대회
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• pp.23-26
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• 1995

The objectives of the present study are 1)to find the effect of the diameter of transpedicular screws on their fixational strength in pedicles under static pull-out loading, 2)to determine the biomechanical correlation between the pedicle diameter and the screw diameter, and 3)to find the effects of other factors in the screw design, such as materials, screw pitch, thread height and shape on their fixational strength. Biomechanical tests (Test I) were performed to evaluate the effect of the screw diameter on pull-out strength by using 60 porcine pedicls and six groups of custom-made pedicle screws with different diameters (the major and the minor diameter of the screws used in the testing varied from 4mm upto 9mm and from 3mm upto 8mm, respectively) while all other factors (materials, screw pitch, thread height and shape etc.) were fixed. In Test II, by using 61 porcine pedicles, the relationship between the ratio of the pedicle diameter and the screw diameter(=aspect ratio) of the custum-made screw and the pull-out strength of the screw was investigated. Test III was performed with 94 porcine pedicles and 8 different types of the commercial screws from 6 major productors in order to determine the effect of the screw diameter, pitch and the thread shape on the pull-out strength of the screw, respectively. The results of Test I showed that the axial pull-out resistance of the screw could be increased prportionaly to the screw diameter(P<0.05). But this increase in the pull-out resistance did not found when the screws of 4mm or 9mm in the diameter were employed. It was found from the results of Test II that the screws had its maximum pull-out resistant force when the aspect ratio ranging 40 - 69% (P<0.05). based on the results for the major diameter against the minor diameter of screw, the maximal pull-out resistance was found at 60-65% (P<0.05). According to these biomechanical testing results, it seems that the screw with a moderately large pitch is more desirable and the buttress-shaped screw can provide stronger fixation than the V-shape one can, if other designal factor and conditions were fixed.

• Elastomers and Composites
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• 제33권2호
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• pp.93-102
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• 1998

In electric cable industries, the curing extent of the rubber materials covering the electric cores gives an significant effect on their final performance. The curing extent of rubber is controlled mostly by pull-out velocity of cable in the extrusion process. The final curing extent may be different for different radial positions inside the rubber because of the non-uniform temperature distributions during the curing process. In this contribution, the prediction of curing extent distribution throughout the radial direction of rubber is represented when the cable is passing through the steam curing zone with a fixed pull-out velocity. The prediction of the optimum pull-out velocity for the desired curing extent distribution is also reported. The steady-state heat balance was developed for the curing and cooling processes in which the pull-out rubber was cured by high temperature steam and then cooled by ambient water. A few essential material properties such as density, specific heat, and thermal conductivity were measured to analyze the temperature distribution during the curing and cooling processes. The times to reach 90% curing extent at varying temperatures were measured and used to determine the final cure extent distribution inside the rubber.

• 대한치과교정학회지
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• 제29권4호
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• pp.503-510
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• 1999

이 연구의 목적은 II급 부정교합의 치료를 위해 경부견인 헤드기어(cervical pull headgear)를 사용할 때, 치료에 불리한 요인으로 작용한다고 언급되는 효과들이 실제로 발현되는지의 여부와 안모의 성장유형에 따라 그 차이가 존재하는 지를 알아 보고자 함에 있다. 이를 위해서 삼성서울병원 치과교정과에서 II급 부정교합으로 진단되어 경부견인 헤드기어로 치료받은 환자중, 성장기에 있으면서 비발치 치료를 받은 환자를 연구대상으로 선별하였다. 그리고 연구대상을 "후안면/전안면 고경비" 에 따라 수직성장군과 수평성장군으로 분류하였다. 수직성장군 15명(남자 5명, 여자 10명)과 수평성장군 11명(남자 4명, 여자 7명)의 치료전, 후의 두부방사선규격사진상에서 SN-PP angle, SN-GoGn angle, SN-MP angle, PFH/AFH ratio, SN to 6, PP to 6 등을 계측하고, 비교분석하여 다음의 결과를 얻었다. 1)수직성장군에서 구개평면이 전하방으로 경사되었다. 2)수평성장군에서 후안면/전안면 고경비가 증가하였다. 3)수직성장군과 수평성장군 모두에서 하악평면각은 변화하지 않았다. 4)상악대구치의 정출양에 있어서 수직성장군과 수평성장군의 차이는 없었다.

• Corrosion Science and Technology
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• 제11권5호
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• pp.165-172
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• 2012

The corrosion resistance of epoxy-coated carbon steel was evaluated. The carbon steel surface was subjected to different treatment methods such as steel grit blasting with different size, steel shot ball blasting and power tool treatment. To study the effect of the treatments, the topology of the treated surface was observed by optical 3D microscopy and a pull-off adhesion test was conducted. The corrosion resistance of the epoxy-coated carbon steel was further examined by electrochemical impedance spectroscopy (EIS) combined with hygrothermal cyclic testing. The results of EIS indicated that the epoxy-coated carbon steel treated with steel grit blasting showed an improved corrosion resistance compared to untreated epoxy-coated surfaces or surfaces subjected to shot ball blasting and power tool treatments.

• Design & Manufacturing
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• 제10권3호
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• pp.46-50
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• 2016

Laminate products for motor core are developed with a structure in which the importance of quality level and clamping force is influenced by the recent performance and safety of the product. It has been confirmed that the accuracy of the mold is emphasized, and that the accuracy of the tightening force produced by the stacked product for the motor core is greatly influenced by the change in the bottom dead center displacement of the aged high speed press. The reason why setting the mold, and test the effect of bottom dead center of high speed press is to improve product pull force in embossing process at mold. We have applied the system to minimize the effect on the damping displacement under the dynamical degree of the equipment by applying the emboss complement device which can test the influence and complement in the process.

• 한국소음진동공학회논문집
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• 제15권11호
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• pp.1276-1286
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• 2005

In this paper, the dual stage interaction between the coarse actuator and the fine actuator of an optical disk drive is studied, and the new control method to enhance the track pull-in performance using fine actuator control is proposed. First, the dynamic analysis for the dual stage and the experiments to find the each actuator dynamics are performed. From the experiments, some physical parameters of the actuators were derived, then, some simulations are performed to find the interaction effect of the fine actuator during seek motion. Second, the center servo which suppresses the vibration of fine actuator during seek motion is designed and evaluated. And the fine actuator control to reduce the relative velocity between the target track and beam spot is proposed. From simulations, we show that fine actuator control which has same frequency and same phase of the disturbance is effective to reduce the relative velocity, and this result leads to track pull-in enhancement. Hence, the proposed control method is good approach to improve the track pull-in performance. Finally, the realization of the proposed method and some comments of it are briefly discussed.