적응 루프법을 이용한 진화적 구조 위상 최적설계

황승민,박재용,임민규,오영규,한석영 한국공작기계학회 2009 한국공작기계학회 춘계학술대회논문집 Vol.2009 No.-

This paper presents a reliability-based topology optimization (RBTO) using bi-directional evolutionary structural optimization (BESO). Topology optimization is formulated as volume minimization problem with probabilistic displacement constraint. Young's modulus, external load and thickness are considered as uncertain variables. In order to compute reliability index, four methods, i.e., RIA, PMA, SLSV and ADL(adaptive-loop), are used. Reliability-based topology optimization design process is conducted to obtain optimal topology satisfying displacement and reliability index constraints with the above four methods, and then each result is compared with respect to numerical stability and computing time.

유리 성형용 금형의 균열 발생 기구

황규홍,송동환,양권승,이종국 조선대학교 생산기술연구소 2005 生産技術硏究 Vol.27 No.2

Microstructure of glass-forming mold have influence on the mechanical properties such as hardness, and life span of the glass-forming mold is strongly dependent on its microstructure. The glass-forming mold with guaranteed tool life requires fine particle size and homogeneous distribution of Cr precipitates in the matrix. In this study, mechanism on the crack creation of the glass-forming mold made in Korea (K-mold) was compared to the one glass-forming mold made in Japan (J-mold). SEM observation revealed that the particle size of the Cr precipitates in J-mold was smaller than that in K-mold, in addition the size distribution of J-mold was narrower than that of K-mold, resulting in long life of J-mold. Therefore, it was confirmed that the microstructure of the glass-forming mold related to Cr precipitates was one of the important parameters to improve the quality of products.

Hanger로 보강된 스터드 접합부의 인장거동에 관한 실험적 연구

박휘규,김승훈,이리형,이용택,황홍순,이정희 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1(구조계)

This paper presents the tensile behavior of the stud connection between reinforced concrete(RC) and steel members. Hanger reinforcements are placed around the studs to transfer the tensile loads to the opposite side of the concrete member. Six specimens, of which variables were arrangement details of hanger reinforcements and studs. Tensile test results show that hanger reinforcements are effective to increase tensile strength and ductility. Test tensile strengths of specimens are compared with the nominal strengths by ACI codes(ACI 318-02, ACI 349-99) and PCI 1999.

心臟組織 Cyclic 3':5'-Nucleotide Phosphodiesterase- Activator의 Methylation

李聖鎭,林圭,黃炳斗 충남대학교 의과대학 지역사회의학연구소 1986 충남의대잡지 Vol.13 No.1

Cyclic 3':5'-nucleotide phosphodiesterase-activator(calmodulin) has been purified from bovine heart approximately 850-fold, and investigated methylation of calmodulin by protein methylase Ⅱ and the effect on the calmodulin-induced activation of phosphodiesterase by methylated calmodulin. Calmodulin-induced activation of phosphodiesterase by purified calmodulin is stimulated 3.1-fold and its saturating concentraticn is about 0.4 ㎍ protein. The purified calmodulin appears single protein band by SDS/polyacryamide gel electrophoresis (pH 2.4) and the calmodulin-induced activation of phosphodiesterase is completely inhibited by adding 100 ㎍ of fluphenazine and 1 mM of EGTA. The relative substrate efficiency of calmodulin by protein methylase Ⅱ is about 70% compare with histone IIA-S. The methylated calmodulin inhibits about 20% calmodulin-induced activation of phosphodiesterase compare with that of nonmethylated calmodulin. Methylation rate of calmodulin is constant, independant of Ca^2+ presence. Calmodulin-induced activation of phosphodiesterase by methylated calmodulin is completely inhibited in the presence of 1 mM EGTA. From the above results, inhibitory mechanism of calmodulin-induced activation of phosphodiesterase by methylated calmodulin is discussed.

ESO기법을 이용한 신뢰성 기반 형상 최적설계

오영규,박재용,황승민,임민규,박재용,한석영 한국공작기계학회 2009 한국공작기계학회 춘계학술대회논문집 Vol.2009 No.-

This paper presents a reliability-based shape optimization (RBSO) using the evolutionary structural optimization (ESO). An actual design involves uncertain conditions such as material property, operational load and dimensional variation. The deterministic optimization (DO) is obtained without considering uncertainties related to uncertainty parameters. However, the RBSO can consider the uncertainty variables because it has the probabilistic constraints. In order to determine whether the probabilistic constraint is satisfied or not, simulation techniques and approximation methods are developed. In this paper, the reliability-based shape design optimization method is proposed by utilizing the reliability index approach (RIA), performance measure approach (PMA), single-loop single-vector (SLSV), adaptive-loop (AOL) are adopted to evaluate the probabilistic constraint. In order to apply the ESO method to the RBSO, a sensitivity number is defined as the change in the displacement. Numerical examples are presented to compare the DO with the RBSO. The results of design example show that the RBSO model more reliable than deterministic shape optimization.

전절권 VRM에서의 상호 및 자기 인덕턴스의 산정에 관한 연구

백승규,황영문 釜山大學校生産技術硏究所 1996 生産技術硏究所論文集 Vol.51 No.-

VRM은 다른 전동기에 비해 높은 자속밀도에서 운전시키는 단방향 전동기구이다. 또한 VRM의 전동력은 자기회로에서 릴럭턴스를 최소로 하는 방향으로 발생시킨다. 따라서 인던턴스의 적절한 산정은 VRM의 운전특성을 결정짓는 중요한 요소이다. 본 논문에서는 전절권 VRM의 자기 및 상호 인덕턴스를 자기회로에서 자기포화를 고려한 퍼미언스법으로 산정하고 그 타당성을 실험으로써 입증하였다. A VRM is single excited machine with high saturation. It's torque is developed by tendency for the magnetic circuit to adopt a configuration of minimum reluctance. Therefore, calculating the inductance is main factor in the study of VRM. This paper suggests the self and mutual inductance estimation method in Full-pitched winding VRM as permeance method considering the saturation in magnetic circuit. And the validity of the suggested method is verified through the test result.

제4경추의 형태와 초경을 통한 성숙지표에 관한 연구

이규홍,황용인,김윤지,박양호,백승학,차경석 대한치과교정학회 2008 대한치과교정학회지 Vol.38 No.1

본 연구는 측모 두부 규격 방사선사진을 이용하여 성장 중인 아동의 제4경추 형태를 경추 몸체부 하연의 만곡 정도에 따라 분류하고 초경의 시기와 수완부 골 성숙 단계를 평가하여, 성장 중인 아동의 골격적 부정교합의 진단 및 악정형 치료를 위한 성장 시기 평가에 제4경추의 형태 변화가 진단의 참고자료로 활용될 수 있는지를 연구하였다. 11-14세 여자 환자 중, 같은 날짜에 촬영된 측모 두부 규격 방사선사진과 수완부 방사선사진이 모두 있는 81명을 대상으로 환자의 측모 두부 규격 방사선사진상 제4경추 몸체부 하연의 만곡 정도에 따라 세 그룹으로 분류하였다. (Group A - 제4경추 몸체부 하연의 만곡 정도가 1.05 mm 이하, Group B -제4경추 몸체부 하연의 만곡 정도가 1.05- 2.07 mm 사이, Group C -제4경추 몸체부 하연의 만곡 정도가 2.07 mm 이상)세 그룹에서 각각 제4경추 몸체부의 수직 길이, 수평 길이, 수직/수평 비율, 초경의 시기, 수완부 골 성숙 단계를 측정한 결과 다음과 같은 결론을 얻었다. 평균 수완부 골 성숙 단계는 Group A가 SMI 5.67 ± 2.57단계, Group B는 SMI 8,73 ± 2.41 단계, Group C는 SMI 10.00 ± 1.47단계로 나타났다. GroupA에서 Group B, Group C로 갈수록 제4경추의 수직 길이, 수평 길이, 수직/수평 비율, 수완부 골 성숙 단계에 있어서 각각 유의하게 더 큰 값을 보였다. 본 연구대상 아동의 평균 초경 시기는 11.64 ± 0.92세를 보였다. 제4경추 몸체부 하연의 만곡 정도, 수직 길이, 수평 길이, 수직/수평 비율은 수완부 골 성숙 단계와 각각 서로 유의한 양의 상관관계를 나타냈다. 초경을 경험한 그룹이 초경을 경험하지 않은 그룹에 비해 제4경추의 수직 길이, 수평 길이, 수직/수평 비율, 수완부 골 성숙 단계에 있어서 유의하게 큰 값을 보였다. 연구 결과 측모 두부 규격 방사선사진상 제4경추 하연의 만곡 깊이가 2.07 mm 이상인 경우 성장의 완료 단계에 가까운 시기로 나타나 이 시기의 악정형적 치료는 큰 효과를 얻을 수 없을 것으로 사료된다. Objective: This study analyzed the morphologic changes of the fourth cervical vertebra body to determine the skeletal age of orthodontic patients during growth. Methods: Eighty-one female patients aged from 11 to 14 who had cephalograms taken on the same day were examined. The subjects were divided into three groups depending on the depth of the concavity of the lower border of the fourth cervical vertebra (Group A: less than 1.05 mm, Group B: 1.05 - 2.07 mm, Group C: greater than 2.07 mm). Menarcheal timing, SMI stage, length, width and ratio of length and width of the fourth cervical vertebra body were analyzed and the following results were obtained. Results: The average SMI stage of group A,B and C were 5.67 ± 2.57, 8.73 ± 2.41, and 10.00 ± 1.47, respectively. Length, width, ratio of length and width, and SMI stage were greater in group B than group A and in group C than group B. Mean menarcheal timing was 11.64 ± 0.92 years. Concavity depth, length, width, ratio of length and width showed a significant positive correlation with SMI stage, especially with the concavity depth. Conclusion: The results of this study propose a simple method for determining the timing of orthopedic treatment by measuring the concavity depth of the fourth cervical vertebra on the cephalogram.

캐쉬를 이용한 RAID5상에서 작은 쓰기 문제의 성능 분석

최황규,서주하,이승택 江原大學校 産業技術硏究所 1995 産業技術硏究 Vol.15 No.-

In this paper we evaluate the performance of the cached RAID5 which uses the parity cache and the data cache to overcome the small write problem. From the result of the simulation study we show that the cached RAID5 provides performance improvement with reasonable cache size.

구강내 결손부에 적용된 연조직 재건술식들에 대한 임상적 고찰

김욱규,이승환,황대석,김용덕,신상훈,김종렬,정인교 부산대학교 병원 암연구소 2007 부산대병원학술지 Vol.- No.21

To evaluate criteria, indications, and prognosis of the various reconstructive methods on the patients with intraoral soft tissue defect who had been treated at Dept. of Oral and Maxillofacial Surgery, Pusan National University Hospital from 2003 to 2005, we have reviewed the clinical data of the patients and analysed. The results were as follows: 1. Tongue flaps have been mainly applied on anterior portion of palate and maxilla. The survival rate was high percent, but the cooperation of patient was inevitable for the success. 2. Palatal mucosa rotational flaps were available on relative large defect on palate, oroantral fistula site. The side effect was a scaring band from secondary healing on denuded donor palate site. Sometimes the band came to be a hinderance to swallowing, phonation. 3. The application of free skin graft on entire maxilla site , palate was possible. The skin from thigh, abdomen could be applicable on fixed or movable tissues. The advantages of abdominal skin were easy harvest and direct donor site closure. 4. Forearm free flap was a workhorse flap for everywhere in intraoral defects. We had used the flap on cheek, floor of mouth, tongue without any significant complications. But the application of the flap was required for long operation time, which was disadvantageous to the old, weak patients. 5. Cervical platysmal flap could be easily applicable for buccal cheek, floor of mouth after excision of the cancer lesion. the design of the flap could be made simultaneously on neck dissection, but the danger of cancer remnants on the flap always might be remained. 6. Buccal fat pad pedicled flap must have been a primary flap for repair of oroantral fistula especially on posterior maxilla. The flap survival will be expected if the considerations for above reconstructivε methods on site, size, condition of defects primarily could be made.

Sertoli 세포의 생리기능 및 호르몬에 의한 조절

임규,박청,윤경아,윤은진,박종일,박승길,황병두 대한내분비학회 2003 Endocrinology and metabolism Vol.18 No.2