해양플랜트 상구구조물의 중량 절감을 위한 알루미늄 핸드레일 적용을 위하여, 소재의 항복강도 향상 및 관련 국제기준에 부 합한 강도평가를 통하여 설계가 이루어지고 있다. 기존에 해양프로젝트에 설치된 알루미늄 핸드레일은 플랫폼에 설치 시 소켓에 볼트 연 결되며, 소켓의 설계 정도에 따라서 핸드레일 처짐 량이 크게 좌우된다. 그러나 국제기준에서는 소켓에 대한 중요성 언급이 없으며, 별도 의 평가 절차나 기준도 모호하다. 따라서 본 연구를 통해서 핸드레일 소켓 설계 시 고려해야 하는 주요 인자들에 대한 강도 해석을 수행 하고, 최적의 치수를 도출하였다. 개발모델의 구조 안전성을 확보하기 위하여, 실험을 통한 검증을 수행하였고, 국제기준에서 요구하는 허용 처짐 이내에서 모두 만족함을 확인하였다. 개발된 국산화 모델은 기존 외국 제조사와 비교하여 가볍고, 생산성이 향상되어 향후 많 은 분야에서 사용이 될 것으로 판단된다.

Extended PE double-walled pipe is a technology that hollow walled pipe widens hollow wall to the side extruded as a square and extrudes the form added with a stiffener of I-BEAM shape from the time of initial pressing out when producing existing double walled pipe. It can improve production speed 1.6 times faster. Plastic pipes used in study were PE pipe, especially HDPE pipe that is safe from reproduction of seaweed and bacteriomycota and can be used semi permanently as a few corrosion by corrosive substance existing in soil is made. The purpose of this study is to decrease production time and increase outputs by extending width of extruding side 1.5 times wider when producing PE double walled pipe through making existing double walled pipe into extended PE double wall. Also, it is aimed to develop an extended PE double-wall pipe that can eliminate causes of defect occurred by middle pipe wound around with drawing machine 90°when producing existing goods.

PE pipes have excellent mechanical and chemical properties and are widely used as water and sewer pipes. The pipes are cut and transported 6 meters in length to facilitate transport and operation. Transferred pipes are joined just before reclamation, resulting in long working hours and environmental contamination due to leakage due to poor coupling. Additional costs are also incurred for the re-work. In this study, we developed a device that can combine the PE pipes and Sockets. Structural safety was verified through structural analysis. In combination with socket and pipe, there is no defect in joint and watertight test shows no leakage.

Socket sclerosis can be an obstacle for orthodontic space closure, however, the precise histomorphogenetic mechanism has not been elucidated up to date. A 73 years old female complained of dull pain on palpation in the extraction site of the left maxillary first molar, and uncomfortable to use her complete denture. In panoramic X-ray view the socket sclerosis was clearly demarcated as a radiopaque outline of extracted root. In histological examination the socket sclerosis showed the basophilic deposition of cementum- like materials in the peripheral rim of trabecular bones instead of eosinophilic osteoid materials for intramembranous ossification. In the immunohistochemical staining for osteogenetic proteins, BMP-2 was strongly positive in the peripheral rim of trabecular bone, in which RANKL and osteoprotegerin were also consistently positive. Particularly, versican, a marker of cementum was also positive in the peripheral rim of the trabecular bone. Therefore, it is presumed that the trabecular bones of socket sclerosis were hypermineralized by cementoid ossification, producing cementum-like materials by osteoblasts/cementoblasts derived from the previous periodontium.

Spring constants (displacement per unit applied load) of MEMS socket pins of given structures were computed by theoretical analysis and confirmed by the finite element method (FEM). In the theoretical analysis, the displacement of pins was calculated based on the 2-dimensional bending theory of the curved beam. For the 3-dimensional modeling, CATIA was used. After modeling, the raw data were transferred to ANSYS, which was employed in the 3-dimensional analysis for the calculation of the stress and strain and loaddisplacement The theoretical analysis and the FEM results were found to agree, with each showing the spring constants as 63.4 N/m within a reasonable load range. These results show that spring constants can be easily obtained through theoretical calculation without resorting to experiments and FEM analysis for simple and symmetric structures. For the some change of shape and structural stiffness, this theoretical analysis can be applied to MEMS socket pins.

BGA test sockets failed earlier than the expected life-time due to abnormal signal delay, shown especially at the low temperature (-50˚C). Analysis of failed sockets was conducted by EDX, AES, and XRD. A SnO layer contaminated with C was found to form on the surface of socket pins. The formation of SnO layer was attributed to the repeated Sn transfer from BGA balls to pin surface and instant oxidation of fresh Sn. As a result, contact resistance increased, inducing signal delay. Abnormal signal delay at the low temperature was attributed to the increasing resistivity of Sn oxide with decreasing temperature, as manifested by the resistance measurement of SnO2.

This study examined the effects of socket flexion angle in trans-tibial prosthesis on stump/socket interface pressure. Ten trans-tibial amputees voluntarily participated in this study. F-socket system was used to measure static and dynamic pressure in stump/socket interface. The pressure was measured at anterior area (proximal, middle, and distal) and posterior area (proximal, middle, and distal) in different socket flexion angles (5°, 0°, and 10°). Paired t-test was used to compare pressure differences in conventional socket flexion angle of 5° with pressures in socket flexion angles of 0° and 10° (α=.05). Mean pressure during standing in socket flexion angle of 10° decreased significantly in anterior middle area (19.7%), posterior proximal area (10.4%), and posterior distal area (16.3%) compared with socket flexion angle of 5°. Mean pressure during stance phase in socket flexion angle of 0° increased significantly in anterior proximal area (19.3%) and decreased significantly in anterior distal area (19.7%) compared with socket flexion angle of 5°. Mean pressure during stance phase in socket flexion angle of 10° decreased significantly in anterior proximal area (19.6%) and increased significantly in anterior distal area (8.2%) compared with socket flexion angle of 5°. Peak pressure during gait in socket flexion angle of 0° increased significantly in anterior proximal area (23.0%) compared with socket flexion angle of 5° and peak pressure during gait in socket flexion angle of 10° decreased significantly in anterior proximal area (22.7%) compared with socket flexion angle of 5°. Mean pressure over 80% of peak pressure (MP80+) during gait in socket flexion angle of 0° increased significantly in anterior proximal area (23.9%) and decreased significantly in anterior distal area (22.5%) compared with socket flexion angle of 5°. MP80+ during gait in socket flexion angle of 10° decreased significantly in anterior distal area (34.1%) compared with socket flexion angle of 5°. Asymmetrical pressure change patterns in socket flexion angle of 0° and 10° were revealed in anterior proximal and distal region compared with socket flexion angle of 5°. To provide comfortable and safe socket for trans-tibial amputee, socket flexion angle must be considered.

The paper proposes a stiffness measurement device composed of a measurement part including six indenters and a fixing part including four fixtures. The device is able to make simultaneously measurements of the stiffness of human arm. The six indenters make use of both position and force control schemes sequentially whenever needed. In addition, the loadcells and the digital encoders are attached to the indenters and electric motors, respectively, so that the data can be provided in real time. On the end of the indenter, two-axis potentiometer is attached in order to measure the angle difference between the applied force axis and the axis normal to the skin of human arm, and to convert the force measured on the loadcell into the actual applied force to skin. For this purpose, the mapping between the voltage output and the angle of potentiometer was obtained by fitting it for each axis. Ultimately, the measurement device was able to measure the stiffnesses of six regions of human arm.