• Earthquakes and Structures
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• 제11권3호
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• pp.421-443
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• 2016

When conducting seismic assessment of an asymmetric building, it is essential to carry out three-dimensional analysis considering all the possible directions of seismic input. For this purpose, the author proposed a simplified procedure is to predict the largest peak seismic response of an asymmetric building subjected to horizontal bidirectional ground motion acting in an arbitrary angle of incidence in previous study. This simplified procedure has been applied to torsionally stiff (TS) asymmetric buildings with regular elevation. However, the suitability of this procedure to estimate the peak response of an asymmetric building with vertical irregularity, such as an asymmetric building with setback, has not been assessed. In this article, the pushover-based simplified procedure is applied to estimate the peak response of asymmetric buildings with bidirectional setback. Nonlinear dynamic (time-history) analysis of two six-storey asymmetric buildings with bidirectional setback and designed according to strong-column weak beam concept is carried out considering various directions of seismic input, and the results compared with those estimated by the proposed method. The largest peak displacement estimated by the simplified method agrees well with the envelope of the dynamic analysis response. The suitability assessment of the simplified procedure to analysed building models is made as well based on pushover analysis results.

• 설비공학논문집
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• 제11권2호
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• pp.250-261
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• 1999

Based on a set of performance plots relating the design variables to the imposed conditions, an easy-to-use and versatile design procedure for chevron-type multipass plate heat exchangers is developed. In order for the present procedure to cover multipass with unequal passes and non-unity ratio of heat capacity rate, each stream number of transfer unit is adopted as the basic design variable instead of the exchanger number of transfer unit. It is found that there exists a unique relation between the stream and exchanger number of transfer units regardless of the chevron angle and the plate length. In addition, for a given value of the pressure drop the heat transfer area per unit mass flow rate can be expressed in terms of the stream number of transfer unit only. These two relationships in the form of simple plots constitute the framework of design. The sample results in comparison with the available data indicate that the present procedure includes the previous ones as a subset, and that every design method is affected essentially by the selection of specific correlations for the heat transfer coefficient and the friction factor.

• 전기학회논문지
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• 제61권1호
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• pp.7-15
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• 2012

In this paper a process of determination for thyristors operating with optimal angle is described. The proposed method is based on the trade-off between the cost(due to rating and loss) and controllability of the system. Large control angle increases controllability of HVDC system and also increase the rating of the system which leads to a high price. Therefore it is important to determine a control angle at a first step of design procedure. This paper shows a rating trend of C.Tr, Valve and Filter due to control angle variation, and then introduces a determination process of the HVDC operating angle.

• 대한족부족관절학회지
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• 제16권1호
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• pp.31-37
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• 2012

Purpose: The purpose of our study is the comparison of radiological and clinical outcomes between modified distal chevron osteotomy and proximal metatarsal osteotomy for the patients who had moderate to severe hallux valgus deformity. Materials and Methods: In this retrospective study, we included 54 patients (65 feets) who underwent the operation of moderate to severe hallux valgus in our hospital from May 2007 to August 2010. Our study compares two groups. For Group 1, a modified distal chevron osteotmy and a distal soft tissue procedure were done and for Group 2, a proximal metatarsal osteotmy and a distal soft tissue procedure were done. The group 1 were 29 feets; the group 2 were 36 feets, and the average follow up was 9 months. Results: The radiological results show that the hallux valgus angle and the first-second intermetatarsal angle were significantly decreased in two groups. In each parameter, the correction of the hallux valgus angle was $19.1^{\circ}$ (Group 1) and $24.3^{\circ}$ (Group 2), the correction of the first-second intermetatarsal angle was $9.6^{\circ}$ (Group 1) and $10.3^{\circ}$ (Group 2). Shortening of the first metatarsal length was 0.87 mm (Group 1) and 0.77 mm (Group 2). There are no significant clinical results (American Orthopaedic Foot and Ankle Society score, AOFAS score) in two groups. Conclusion: It is thought that a modified distal chevron osteotomy and a distal soft tissue procedure are a considerable operative treatment of moderate to severe hallux valgus deformity because of the similar cilinical results, more simple operative techniques, and less complications than a proximal metatarsal osteotomy.

• 대한족부족관절학회지
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• 제8권1호
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• pp.101-106
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• 2004

Purpose: To determine the efficacy of the SDBBA (Subtalar distraction bone block arthrodesis) procedure on patients with late complication of intra-articular calcaneal fractures including subtalar joint arthritis and anterior ankle impingement syndrome. Materials and Methods: Five cases in which the SDBBA procedure was implemented were followed for more than one year. All five patients were male with an average age of 56. Clinically, the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and the pain score were assessed. Radiographically, the talocalcaneal height and the talar inclination angle were determined. Results: All five patients achieved subtalar joint fusion. The average pre-operative AOFAS score was 22.8 scores (range, 8-32 scores). At last follow-up, these scores improved to an average of 72.4 scores (range, 64-82 scores). The average pre-operative pain score was 8.2 scores (range, 7-10 scores). At last follow-up, these scores improved to an average of 13.2 (range, 12-15 scores). The average pre-operative talocalcaneal height was 72.8 mm (range, 70-77 mm), average post-operative talocalcaneal height improved to 79.8 mm (range, 78-84 mm). At final follow-up, these measurement was slightly decreased to average 78.6 mm (range, 74-83 mm). The average pre-operative talar inclination angle was 13.2 degrees (range, 12-15 degrees), average post-operative talar inclination angle improvedto 19.2 degrees (range, 15-24 degrees). At final follow-up, these measurement was slightly decreased to average 18.6 degrees (range, 12-24 degrees). Four patients achieved successful outcomes. One patient developed a wound infection with subsequent sural neuropathy as well as collapse of the bone graft. Conclusion: This study shows that the SDBBA procedure successfully restores the talocalcaneal height and tibio-talar relationship. This procedure is useful in surgically managed patients with talo-calcaneal height loss and anterior ankle impingement syndrome due to the late complications of calcaneal intra-articular fractures.

• 대한정형외과학회지
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• 제56권6호
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• pp.484-490
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• 2021

목적: 류마티스 전족부 변형은 심한 무지 외반증과 소족지의 갈퀴 족지 변형으로 이루어진다. 저자들은 류마티스 전족부 변형에 대한 변형 Hoffman 술식의 중기 결과를 분석하고자 하였다. 대상 및 방법: 18명, 22예의 환자가 변형 Hoffman 술식 후 최소 2년 이상 추시되었다. 평균 연령은 54.7세였고 평균 추시 기간은 3년 4개월이었다. 임상적으로 시각통증척도와 미국 정형외과 족부족관절학회 점수를 술 전 및 술 후에 비교하였다. 또한 술 후 합병증과 환자의 만족도 및 족저부 굳은살의 소실 여부를 조사하였다. 방사선학적으로 무지 외반각, 제1-2 중족골간각, 제1 족지 지간각, 제1 족지 지간 관절의 관절염 발생 여부, 제1 중족지 관절 족배 굴곡각, 제1 중족지 관절의 유합 기간 등을 측정하였다. 결과: 임상적으로 시각통증척도와 미국 정형외과 족부족관절학회 점수는 술 전 평균 7.1점과 평균 30.3점에서 최종 추시 시 평균 1.5점과 평균 83.1점으로 호전되었다(p<0.001). 술 후 만족도는 전 환자가 만족하였으며, 술 후 족저부 굳은살은 모든 예에서 소실되었다. 방사선학적으로 무지 외반각, 제1-2 중족골간각, 제1 족지 지간각은 술 전 각각 평균 52.8도, 13.3도, 7.5도에서 최종 추시시 16.2도, 8.7도, 14.6도로 변화하였다(p<0.001). 제1 중족지 관절의 족배 굴곡각은 평균 17.2도였으며, 제1 중족지 관절은 평균 11.1주에 유합되었다. 합병증으로 소족지의 거상지 변형이 2예, 창상 문제가 1예, 제1 족지 지간 관절의 관절염이 2예에서 발생하였다. 제1 중족지 관절의 불유합은 관찰되지 않았다. 결론: 류마티스 전족부 변형에 대해 변형 Hoffman 술식은 안전하고 만족스러운 술식으로 사료된다.

• Archives of Plastic Surgery
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• 제36권4호
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• pp.469-474
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• 2009

Purpose: A lower facial contouring surgery has become a commonly performed procedure in Asia. Currently, mandibular angle sagittal ostectomy and botulinum toxin type A treatment are main procedures for aesthetic correction of a broad lower face. There are a few date to show the differences in the mandibular contouring changes between mandibular angle splitting ostectomy and botulinum toxin type A treatment. Facial golden mask is easy to apply, inexpensive, and relatively objective for evaluation of facial contour analysis. This study was designed specifically to compare the changes in lower face width after two different forms of lower facial contouring procedure using facial golden mask. Methods: Seventeen patients, aged 18 to 55 years (mean, 28.6 years), 15 women and 2 men, consented to the study and receive a contouring procedure of lower face. The patients were classified in to 2 groups. In group A, the sample consisted of 10 patients with a prominent squared mandibular angle and mandibular angle splitting ostectomy was performed. In group B, the sample consisted of 7 patients with masseteric hypertrophy and botulinum toxin type A treatment was performed. Photographs of the face were taken to record the facial change at preoperative and postoperative. The postoperative photographs were taken to considered maximal effect at 2 years after surgery in group A and 4.8 months after treatment in group B. The authors applied the facial golden mask to preoperative and postoperative photographs and horizontal ratio, which compares facial width with golden mask width, were calculated. We made an analysis of the result of horizontal ratio using SPSS. Results: Overall average horizontal ratio of pre- and postoperative photos of group A were 1.24 and 1.11, whereas overall average horizontal ratio of pre- and postoperative photos of group B were 1.19 and 1.12. The horizontal ratio decreased 10.24% in group A and 5.93% in group B. There was a statistically significant change in before and after treatment, but there was no significant change in comparing the group A and group B. Conclusions: The result from this study suggest that mandibular angle sagittal ostectomy and botulinum toxin type A treatment showed relatively satisfactory clinical effects on lower facial contouring treatment. There was no statistical significant difference within two lower facial contouring treatment. Facial golden mask is easy to apply, inexpensive, and relatively objective, so we think that facial golden mask is a good method for evaluation of lower facial contouring treatment.

• 한국정밀공학회지
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• 제22권11호
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• pp.190-195
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• 2005

A Femur is the longest and largest bone which supports body in human musculoskeletal structure. Therefore, it may cause heavy loss of blood when it is suffered by a simple or complex fracture, and the complication is very dangerous with a possibility of severe tissue damage. In this study, the femoral cancellous angle change is estimated in order to design the Korean femoral IM nail. Generally, it is various in the size and curvature of femoral cancellous bone depending on patient's body dimension. Therefore surgeon has difficulty in fitting this femoral IM nail to the patient in the surgical procedure. In our study, we tries to estimate femoral lateral curve angle with more precise method based on CT image of the femur and utilize this information on the design of femoral IM nail for Korean patients.

• 한국자동차공학회논문집
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• 제5권5호
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• pp.170-177
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• 1997

In this study, an analysis technique using simple beam model for predicting structure crashworthiness of the passenger car side impacted with an angle by another passenger car was investigated. The simple model was composed of major beam-like side structure which carry almost all side impact load. A procedure of component collapse test, calculation of load carrying capability and dynamic simulation was carryed out sequentially. Transient dynamic algorithms and a computer program to simulate deformations and motions of the impacted car was developed. The developed procedure was applied to a 3 door passenger car side impacted with an angle of 75 degree and the analysis results show good agreements with the actual test results.

• 한국구조물진단유지관리공학회 논문집
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• 제2권3호
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• pp.168-175
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• 1998

This study investigated the structural performance of the precast prestressed cylinder pipe having cracked under construction. The finite element formulation of PPC pipe incorporates Asoild elements using SAP90 program and the radial prestress force was transformed into the eqivalent external pressure. The analytical results were compared with the experimental results of full scale tests on PPC pipes subjected to static load. It is shown that the proposed modelling gives a realistic represention of the actual behavior. The analytical procedure is used to calculate the stresses in the PPC pipes and to check the crack opening under various situations such as bedding angle, earth pressure, and earth cover. Finally, the proposed modelling and analytical procedure should be especially usefull for the safety assessment of the PPC pipes under general loading conditions.