國內化崗岩의 불꽃切削에 관한 考察

박성두 경기대학교경영대학원 1991 最高經營者課程 經營硏究 Vol.2 No.-

플라스마 아크 紛體肉盛法에 의한 Al 合金의 硬化厚膜 合金化層의 形成

박성두,이영호 대한용접접합학회 1993 대한용접·접합학회지 Vol.11 No.2

Effect of Si metal powders addition with the plasma transferred arc(PTA) overlaying process on characteristics of the alloyed layer in aluminum alloy(A5083) has been investigated. The overlaying conditions were 175-250A in plasma arc current, 500mm/min in travel speed, the 5-20g/min in powder feeding rate. Main results obtained are summarized as follows. 1)Sufficient size of molten pool on surface of base metal was required for forming an alloyed layer; in a fixed travel, the formation of alloyed layer with clear and beautiful surface depend upon the plasma arc current and powder feeding rate; the greater plasma arc current and the smaller powder feeding rate were, the better bead was formed. Optimum alloyed conditions by which an excellent alloyed bead obtained was 225A in plasma arc current. PTA process made it possible to form an alloyed layer with up to 67wt% Si. 2)Microstructure in the alloyed layer was in accord with prediction from the Al-Si phase diagram 3)The hardness of the alloyed layer increased in proportion to Si content. 4)As volume fraction of primary Si increased, the specific wearness of the alloyed layer was significantly improved. However, no further improvement was found when the volume fraction was greater than about 30%. 5)Utilizing the PTA process, a crack free alloyed layer with maximum hardness of about Hv 310 could be obtained.

경부운동훈련이 외상 후 스트레스 장애 환자의 경부통증 수준, 우울 요인에 미치는 영향

박성두,신영일,김명준,Park, Sung-doo,Shin, Young-il,Kim, Myung-joon 대한정형도수물리치료학회 2015 대한정형도수물리치료학회지 Vol.21 No.1

Background: This study investigates the impact of the cervical musculoskeletal intervention on post-traumatic stress disorder patient's cervical pain levels and depression factor. Methods: Thrty neck pain patients diagnosed with post-traumatic stress disorder were enrolled. Neck exercise training using a sling system was applied to the experimental group and self-neck movement exercise, modification of the McKenzie exercise, was applied to the control group. Both groups were checked every week whether they performed or not. Both groups performed their exercise for 35 minutes for a time and 3 times per week. Total period of the intervention was 6 weeks. To compare the effects of interventions, threshold of cervical tenderness and depression level were measured before and after the each intervention and also measured at follow-up. Results: Painthreshold of left trapezius showed a significant difference between two groups at three points. It increased 19.71% in the experimental group after the intervention compared to before the intervention. At follow-up it also increased 20.06% in the experimental group. Pain threshold of right trapezius showed a significant difference at three points. It increased 18.35% in the experimental group after the intervention compared to before the intervention. At follow-up it also increased 15.93% in the experimental group. According to the result interaction between groups and measurement time in both side of trapezius was valid. Depression level showed significant difference in the experimental group between three points. It decreased 18.07% after the intervention compared to before the intervention and decreased 15.21% at follow-up. According to the result interaction between groups and measurement time in depression level was valid. Conclusions: This study has important implications as the therapeutic strategy, high potent of improving symptoms, shows effect to a subject who has psychological problem such as posttraumatic stress disorder (PTSD).

편평족에 대한 관절가동술과 자가신장이 요부의 신장성, 요통과 하지 체중부하 차이에 대한 비교 연구

박성두,유달영,Park, Sung-doo,Yu, Dal-yeong 대한정형도수물리치료학회 2017 대한정형도수물리치료학회지 Vol.23 No.2

Background: The purpose of this study was to investigate the relationship between the spine and the flat-foot, the stability and the alignment of the posture of the neck to prevent the alignment of the ankle joint operation and the lower back flexibility of the lumbar region according to the type of treatment using active stretching of the triceps, back pain, and to see how they affect weight bearing differences. Methods: The subjects of this study were 24 chronic low back pain patients. They were randomly divided into experimental group and control group. In the experimental group, ankle joint mobilization and active scraping of triceps were performed three times a week for a total of 6 weeks. The control group was performed in the same way without articulation. The range of flexion and extension motion of the lumbar spine and pain degree and difference of weight-bearing were measured before and after the experiment. Results: The model of ankle joint mobilization and calf muscle elongation of flat foot significantly improved the range of flexion and extension motion of the vertebrae (p<.05) and the VAS and distribution of weight-bearing were decreased in both of two groups (p<.05). In other words, the exercise and mobilization help to recover of the balance of the whole musculoskeletal, the vertebrae. Conclusions: The active exercise of the triceps muscle of the lower leg in this study It affects the flexibility of the lumbar spine, the pain and the difference in the weight support of the lower extremities, when we performed ankle joint mobilization for exercise and cramping, pain and the difference in weight support between the two lower limbs.

旗岩<SUB>기암</SUB>

박성두 문예운동사 2023 수필시대 Vol.21 No.봄

Comparison of Balance and Fall Eff icacy of Virtual Reality Program in Elderly Women with Fall Experience

박성두,김진영,유성훈,양경희,송현승 대한물리치료학회 2014 대한물리치료학회지 Vol.26 No.6

Purpose: The objective of this study was a virtual reality-based balance training program effective for improvement in physicalfunction, examined the balance ability and fall efficacy of elderly women with experienced falls, intending to examine theprogram’ s usefulness as an exercise program to prevent the recurrence of a fall. Methods: The participants were 30 elderly women aged 65 or older who met the conditions. The participants were randomlyassigned to either a balance training group (BT) or a virtual reality-based balance training group (VT) and received the trainingthree times per week, 30 minutes per day, for six weeks. To measure static balance, the Tetrax Portable Multiple System (TetraxLtd, Israel) were used. To measure dynamic balance, the Berg Balance Scale (BBS) and functional reach test (FRT) was used, andregarding fall efficacy, the Korean Fall Efficacy Scale (K-FES) was used. Results: Tetrax significantly improved after the intervention in both the BT group and the VT group (p<0.05). The comparisonbetween the two groups was not significantly. BBS and FRT result significantly improved after the intervention in both the BT andVT groups (p<0.001), while K-FES was significantly ameliorated in the VT group only (p<.05). Comparing the groups, there weremore significant changes in the BBS (p<0.05) and FRT (p<0.01) result of the VT group than the BT group. Conclusion: A virtual reality-based balance training program is considered to be usable as an exercise program to preventrecurrence of falls in elderly women.

최적조건에 의한 펄스형 Nd : YAG 레이저 용접의 온라인 프로세스 모니터링에 관한 연구

박성두 한국기계기술학회 2000 한국기계기술학회지 Vol.2 No.2

PTA법에 의한 Al 합금표면의 Si 합금층 형성과 내마모성 개선

박성두,이영호 대한용접접합학회 1997 대한용접·접합학회지 Vol.15 No.5

The formation of thick alloyed layer with high Si content have been investigated on the surface of Al alloy (A5083) plate by PTA process with Si powder. Hardening characteristics and wear resistance of alloyed layer was examined in relation to the microstructure of alloyed layer. Thick hardened layer in mm-order thickness on the surface of A5083 plate can be formed by PTA process with wide range of process condition by using Si powder as alloying element because of eutectic reaction of Al-Si binary alloy. High temperature and rapid solidification rate of molten pool, which are features of PTA process, enable the formation of high Si content alloyed layer with uniform distribution of fine primary Si paticle. High plasma arc current was beneficial to make the alloyed layer with smooth surface appearance in wide range of powder feeding rate, because enough volume of molten pool was necessary make alloyed layer. Uniform dispersion of fine primary Si particle with about 30${\mu}{\textrm}{m}$ in particle size can be obtained in layer with Si content ranging from 30 to 50 mass %. Hardness of alloyed layer increased with increasing Si content, but increasing rate of hardness differed with macrostructure of alloyed layer. Wear resistance of alloyed layer depended on $V_{si}$(volume fraction of primary Si) and was remarkably improved to two times of base metal at 20-30% $V_{si}$ without cracking, but no more improvement was obtained at larger $V_{si}$.

중학교 실업교육이 공업고등학교 기계과 교육에 미치는 영향에 관한 연구 (1978 . 2)

박성두 대한공업교육학회 1988 대한공업교육학회지 Vol.13 No.2

이 연구는 현행 중학교 공업, 농업, 상업교과 내용과 공업고등학교 기계교과 내용을 비교분석하고 중학교 실업교육이 공업고등학교 기계과 교육에 어떠한 영향을 미치고 있는가를 알아보기 위하여 시도된 것이다. 중학교의 공업·농업·상업교과와 공업고등학교 기계과의 지도목표 및 내용을 비교하여 불 때 농업·상업 교과보다 공업교과가 기계교과에 가장 밀접한 관계가 있으므로 농업·상업교과를 이수한 학생들 보다는 공업을 이수한 학생들이 기계교과 점수의 평균치에서 높게 나타날 것으로 예상했으나 아무런 차이가 없었다. 그러므로, 중학교의 실업교과는 그 명칭에서 시사하는 바와 같이 실업교육을 목적으로 하는 것이 아니고, 장래의 직업 선택과는 관계없이 보통 교양 교육으로서, 실생활에 필요한 기본적 자질 육성에 이바지하는 교과라 할 수 있다. 따라서 중학교 실업교육은 공업고등학교 기계과 교육에 어떠한 영향도 미치고 있지 않다고 말할 수 있다.

가재야, 잘 있느냐

박성두 문예운동사 2022 수필시대 Vol.20 No.가을