常設 科學 클럽 運營을 通한 自主的 探究學習 能力 伸張

서효성 韓國敎員大學校 敎育硏究院 1988 敎員敎育 Vol.4 No.1

이상과 같은 연구의 실행 결과 얻은 결론은 다음과 같다. 1. 과학 클럽 조직 운영은 그 조직 방법과 절차를 이해하고 기초 조사를 비롯한 제반 자료를 정비하여 아동 중심 체제로 전환하고 입부 지도 등 교사의 치밀한 연구와 사전 지도가 충실히 이루어졌을때 클럽 활동의 목적에 맞고 과학 클럽의 자율성이 신장되며 과학 특기아나 우수아들에 대한 지도가 가능하게 된다.

무인 주차 안내시스템 제작

서효성,이정현,강정구 대한전기학회 2018 대한전기학회 학술대회 논문집 Vol.2018 No.11

전력증폭기의 2-톤과 CDMA 혼변조 특성을 동시에 만족시키는 방법에 관한 연구

안효성,조숙희,황문수,서태환,김병철 한국전자파학회 2003 한국전자파학회논문지 Vol.14 No.10

본 논문에서는 전력증폭기의 2-톤 혼변조 신호와 CDMA ACPR 특성 사이의 관계를 고찰하였으며, CDMA ACPR 특성은 3차 혼변조 신호의 크기보다 5차 혼변조 신호의 크기가 더 큰 영향을 미치는 것을 확인하였다. 이에 따라 본 논문에서는 전력증폭기 가 CDMA ACPR 특성 이 규격을 만족하고, 2-톤 특성 중 3차 혼변조 신호가 규격을 만족시키지 못하도록 전력증폭기를 튜닝 한 후 선형화기를 사용하여 3차 혼변조 신호만 개선시킴으로써 2-톤과 CDMA 두 가지 신호에서 규격을 만족시키는 방법을 제시하였다. 본 논문에서 제시된 방법을 전력증폭기에 적용한 결과 2-톤 신호의 3차 혼변조 신호는 20 dB, CDMA ACPR 특성은 전체적으로 약 2 dB 개선되어 두 신호에서 전기적 규격을 만족시키는 것을 확인하였다. In this paper, we investigate the relationship between the intermodulation signal of 2-tone and CDMA spurious emission of HPA. And confirm that the fifth IMD signal of HPA has more important effect upon CDMA ACPR characteristics than the third IMD signal. We present the method for the power amplifier to satisfy the 2-tone and CDMA specification simultaneously, and that is to use the predistorter for improving the third IMD signal of 2-tone for the power amplifier which is tuned to satisfy the CDMA specification and not to satisfy the 2-tone specification. The result by using the method which is presented from this paper shows that the ACPR is improved about 2 dB for CDMA 1FA(frequency allocation) signal and the third IMD signal is improved about 20 dB for CW 2-tone signals and we confirmed the specification is satisfied simultaneously.

Arthroscopic Treatment of Delayed Patella Infera

윤정로,오광준,서효성,양재혁 대한정형외과학회 2014 대한정형외과학회지 Vol.49 No.3

Patella infera (baja) is a rare condition that can result from several etiologies including trauma around the knee. Risk factors include scar tissue formation in the retropatella fat pad, extensor mechanism dysfunction, immobilization in extension position of the knee joint, etc. Unawareness and delayed recognition are known to be associated with long-term disability. In this condition, arthroscopic treatment is generally recommended only for early cases. In this report, we present a case with reasonable outcome of delayed patella infera treated by arthroscopic treatment. Prudent arthroscopic debridement of the responsible scar tissue and accelerated rehabilitation therapy is necessary for achievement of a successful outcome.

4140강에 황동의 육성용접시 발생하는 균열현상 연구

김동국,이성학,서효성 대한금속재료학회(대한금속학회) 1997 대한금속·재료학회지 Vol.35 No.7

An investigation was conducted into the effect of microstructural parameters on the cracking behavior which often occurred in the brass layer softfaced on an AISI 4140 steel substrate. Particular emphasis was placed on a role of the microstructural change, which mostly depended on heat input during softfacing, in the cracking phenomenon. Detailed microstructural analyses of the cracked region showed that cracks were observed to be initiated in the heat-affected region of the 4140 steel, and then propagated into softfaced brass layer, resulting in a surface crack. In the case of the lower heat input, the number of cracks was significantly reduced, although many pores were formed in the softfaced layer because of insufficient melting. These findings suggest that the proper heat input condition must be used considering cracking behavior and softfacing defects.

Navigated Acetabular Cup Fixation for Acetabular Deformity or Revision Total Hip Arthroplasty

윤호현,윤정로,유중진,서효성 대한고관절학회 2014 Hip and Pelvis Vol.26 No.3

Purpose: To evaluate the usefulness of navigated acetabular cup fixation for total hip arthroplasty in patientswith acetabular deformity or revision total hip arthroplasty. Materials and Methods: This study enrolled 28 patients with at least 12 months’ follow-up. The safe zone ofthe acetabular cup was defined as 40。±10。in inclination and 15。±10。in anteversion. The authors used thenavigation and radiographic data to determine whether the acetabular cup was located within the safe zone ornot. To evaluate the clinical outcomes, preoperative and last follow-up Harris hip scores were checked, and theoccurrence of complications was evaluated. Results: According to the navigation data, the mean inclination and anteversion were 38.5。±4.7。(range, 32。-50。) and 16.6。±4.0。(range, 8。-23。), respectively. According to the radiographic data the mean inclination andanteversion were 40.5。±4.6。(range, 32。-50。) and 19.4。±4.2。(range, 8。-25。), respectively. In both cases, allvalues were within the safe zone. Harris hip score was improved in all patients from preoperative 52.3±14.4points (range, 29-87 points) to 88.0±9.0 points (range, 65-99 points) at the last follow-up. There was nodislocation or loosening of both cases. Conclusion: Navigated acetabular cup fixation is a useful technique for total hip arthroplasty in patients withacetabular deformity or revision total hip arthroplasty because it prevents the malposition and related complications.

Arthroscopic Treatment of Delayed Patella Infera

Jung-Ro Yoon(윤정로),Kwang-Jun Oh(오광준),Hyo-Seong Seo(서효성),Jae-Hyuk Yang(양재혁) 대한정형외과학회 2014 대한정형외과학회지 Vol.49 No.3

슬개골 저위증은 외상 등 여러 원인에 의해 발생할 수 있는 드문 질환이다. 슬개골 후방의 지방체의 반흔조직 형성, 신전 기능의 이상, 무릎관절 신전 부위의 고정 등이 잘 알려진 위험인자이다. 이를 인식하지 못하거나 인식이 늦어졌을 경우 장기적인 장애와 연관될 수 있다. 통상적으로 관절경치료는 조기발생인 경우 권유되지만 본 증례에서는 골절 후 발생된 지연성 슬개골 저위증에 대해서 관절경적 치료는 만족스러운 결과를 보여주었다. 관절경을 통한 반흔조직의 변연 절제술과 조기 재활 치료는 만족스러운 결과를 위한 중요한 치료이다. Patella infera (baja) is a rare condition that can result from several etiologies including trauma around the knee. Risk factors include scar tissue formation in the retropatella fat pad, extensor mechanism dysfunction, immobilization in extension position of the knee joint, etc. Unawareness and delayed recognition are known to be associated with long-term disability. In this condition, arthroscopic treatment is generally recommended only for early cases. In this report, we present a case with reasonable outcome of delayed patella infera treated by arthroscopic treatment. Prudent arthroscopic debridement of the responsible scar tissue and accelerated rehabilitation therapy is necessary for achievement of a successful outcome.

대형 튜브 성형체의 후방압출 공정개발

조창연(C. Y. CHO),박성우(S. W. PARK),이종억(J. O LEE),서효성(H. S. SEO),이정민(J. M. LEE) 한국소성가공학회 2010 한국소성가공학회 학술대회 논문집 Vol.2010 No.10

Typically, the thermoplastic material fabrication processes and production time while minimizing the loss of mechanical properties to produce superior products that are known for molding method. The extrusion method with minimal loss of material with excellent mechanical properties and a thin wall thickness to create a large-size Tube is widely used in construction. This study has been reformed for the relation of deformation between a die and products in backward extrusion. Especially, the pressure load and products eject method is very important factor for the improvement of extrusion process. Therefore, we developed a forging die shape for reduce pressure load and optimal product.

고관절 골수정을 이용하여 안정된 원위부 고정을 얻은 대퇴 전자간 골절에서 원위 잠금이 항상 필요한가?

윤호현(Ho Hyun Yun),윤정로(Jung Ro Yoon),서효성(Hyo Seong Seo),유중진(Jung Jin Yu) 대한정형외과학회 2015 대한정형외과학회지 Vol.50 No.1

목적: 대퇴 전자간 골절을 골수정으로 치료 시 원위 잠금이 항상 필요한지에 대해서 알아보고자 하였다. 대상 및 방법: 2010년 4월부터 2013년 6월까지 2세대 골수정으로 안정형 대퇴 전자간 골절들(AO/OTA 31-A1)을 치료하고, 최소 1년 이상 방사선 및 임상 추시가 가능하였던 47예의 방사선적 및 임상적 치료 결과들을 원위 잠금을 사용한 군과 원위 잠금을 사용하지 않은 군으로 분류하여 비교 분석하였다. 결과: 두 군의 방사선적 및 임상적 치료 결과 간에서 통계적으로 유의한 차이는 없었다. 수술 후 대퇴부 동통이 8예(17%)에서 발생하였다. 대퇴골 협부 직경과 사용한 골수정 직경 간 차이는 대퇴부 동통 발생에 통계적으로 유의하였다(Fisher’s exact test, p=0.01). Logistic regression analysis 결과상 대퇴골 협부 직경과 사용한 골수정 직경 간 차이가 대퇴부 동통 발생에 가장 큰 영향을 미치는 통계적으로 유의한 인자였다(p=0.04, odd ratio=27.75). 결론: 2세대 골수정으로 안정형 대퇴 전자간 골절을 치료 시 정복 상태가 만족스럽고 대퇴골 협부 직경과 골수정 직경 차이가 작아서 안정된 원위부 고정을 얻었다고 예상된 경우에 한해서 원위 잠금은 불필요할 수 있다. Purpose: The purpose of this study is to investigate the constant necessity of distal locking when intertrochanteric fracture was treated with an intramedullary hip nail. Materials and Methods: From April 2010 to June 2013, 47 stable intertrochanteric fractures (AO/OTA 31-A1) were treated with second generation intramedullary hip nailing. They were followed-up for more than 12 months. In the first group of 18 cases distal locking was used, and in the second group of 29 cases, distal locking was not used. We compared the radiologic and clinical results of the two groups. Results: Comparison of the two groups of patients showed no difference in terms of radiological and functional results. Postoperative thigh pain developed in eight cases (17%). A statistically difference was observed between isthmic diameter and used nail diameter (Fisher exact test, p=0.01) for postoperative thigh pain. In logistic regression analysis, the difference between isthmic diameter and used nail diameter was the most statistically significant factor in development of postoperative thigh pain (p=0.04, odd ratio=27.75). Conclusion: Our results suggested that the second generation intramedullary hip nail may be successfully implanted without distal interlocking in 31-A1 intertrochanteric femur fracture when the reduction status was satisfactory and stable fixation of the distal area was estimated by less than 3 mm difference between isthmic diameter and used nail diameter.

생수통 설치 카트

홍혜준(H.J. Hong),노태경(T.K. Noh),신지훈(J.H. Shin),문민주(M.J. Moon),김재원(J.W. Kim),최준열(J.Y. Choi),서효성(H.S. Seo),박태조(T.J. Park) 한국기계가공학회 2017 한국기계가공학회 춘추계학술대회 논문집 Vol.2017 No.4