A load increment method for ductile reinforced concrete (RC) frame structures considering strain hardening effects

Gunhan Aksoylu, M.,Girgin, Konuralp Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.38 No.2

This study introduces a new load increment method for the ductile reinforced concrete (RC) frame structures by including strain-hardening effects. The proposed method is a nonlinear static analysis technique employed for RC frame structures subjected to constant gravity loads and monotonically increasing lateral loads. The material nonlinearity in RC structural elements is considered by adopting plastic hinge concept which is extended by including the strain hardening as well as interaction between bending moment and axial force. Geometric non-linearity, known as second order effect, is implemented to the method as well.

부분 정보에 기반한 효과적인 음악 무드 분류 방법

박근한(Gunhan Park),박상용(Sang-Yong Park),강석중(Seok-Joong Kang) 한국멀티미디어학회 2007 멀티미디어학회논문지 Vol.10 No.3

기술의 발전으로 인하여, 대용량의 음악 데이터들을 저장하고 검색하는 것이 중요하게 되었다. 그러나 음악데이터들을 손쉽게 분류하고 검색하기 위한 방법론에 대한 집중적인 연구는 이루어 지지 않고 있다. 본 논문에서는 내용기반의 음악 분류/검색에 대한 새로운 방법론을 제안한다. 기존의 분류화 (classification) 방법들이 음악파일 전체에 대해서 수행하는데 비해 음악파일의 부분만을 분석하여 비슷한 성능을 낼 수 있다는 것을 보여 주었고, 소리의 톤 (tone) 표현에 기반한 새로운 피쳐를 제안하여 기존의 피쳐들에 비해 효과적으로 분류를 할 수 있다는 것을 보여주었다. 또한 속도향상을 위한 여러가지 방법론들을 적용하여 실 제품 적용 시 보다 효과적인 방법론이 될 수 있음을 보여주었다. 제안한 방법론을 MuSE (Music Search/Classification Engine)엔진으로 구현함으로써 PC와 PDA상에서 잘 동작함을 보여주었다. According to the recent advances in multimedia computing, storage and searching technology have made large volume of music contents become prevalent. Also there has been increasing needs for the study on efficient categorization and searching technique for music contents management. In this paper, a new classifying method using the local information of music content and music tone feature is proposed. While the conventional classifying algorithms are based on entire information of music content, the algorithm proposed in this paper focuses on only the specific local information, which can drastically reduce the computing time without losing classifying accuracy. In order to improve the classifying accuracy, it uses a new classification feature based on music tone. The proposed method has been implemented as a part of MuSE (Music Search/Classification Engine) which was installed on various systems including commercial PDAs and PCs.

Buckling analysis of functionally graded material grid systems

K. Darılmaz,M. Gunhan Aksoylu,Yavuz Durgun 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.54 No.5

This paper aims to fill the technical gap on the elastic buckling behavior of functionally graded material (FGM) grid systems under inplane loads on which few research has been done. Material properties of an FG beam are assumed to vary smoothly in the thickness direction according to power and exponential laws. Based on a hybrid-stress finite element formulation, buckling solutions for FGM grid systems consisting of various aspect ratios and material gradation are provided. The numerical results demonstrate that the aspect ratio and material gradation play an important role in the buckling behavior of FGM grid systems. We believe that the new results obtained from this study, will be very useful to designers and researchers in this field.

동적 탐색 영역 조정을 기반으로 하는 블럭 정합 알고리즘

오황석(Hwang-Seok Oh),박근한(Gunhan Park),이흥규(Heung-Kyu Lee) 한국정보과학회 1998 정보과학회논문지(B) Vol.25 No.5

본 논문에서는 블럭 정합 알고리즘으로 많이 사용되는 전역 탐색 기법의 계산량을 줄이기 위해서 블럭 유사성을 이용한 동적 탐색 영역 조정 방법을 이용한 움직임 추정 기법을 제안한다. 제안한 기법은 (1)블럭 유사성과 DBD를 이용한 새로운 탐색 원점 설정, (2)블럭 유사성에 반비례하는 탐색 영역의 크기 설정, 그리고 (3)비디오 영상의 특성을 반영하도록 임계값 수정의 단계를 거쳐 수행된다. 제안된 기법은 전역 탐색 기법뿐만 아니라 TSS, NTSS, OTS, PHODS 등과 같은 여러가지 빠른 알고리즘에 쉽게 적용될 수 있으며, 계산량과 화질, 국부 최적 문제를 효과적으로 극복할 수 있다. 여러가지 비디오 영상을 이용한 실험 결과는 제안된 기법이 전역 탐색(FSA), 삼단계 탐색(TSS), 그리고 새로운 삼단계 탐색 기법(NTSS)에 적용되었을 경우, 초기에 탐색 영역을 설정하는 방법, 적응적 조정 기법[13]에 비하여 각 블럭 당 정합 블럭 수, 절대값 오차 측면에서 좋은 성능을 보여준다. Dynamic search window adjustment for block-matching algorithm(BMA) based on the block similarity to overcome the computational complexity of full search BMA is presented. The proposed method for adjustment of the size of search window is performed with three steps. (l)Set new search origin based on block similarity and displaced block difference(DBD), as a displacement of the block which has smaller DBD between the zero displaced and the displaced as much as adjacent block's motion vector that has maximum block similarity. (2)Adjust the size of search window in inverse proportion to block similarity, and (3)Update the thresholds for accommodation to a given image sequence. The technique can be easily applied for full search BMA or several fast search algorithms such as TSS, NTSS, OTS, PHODS, etc to get more efficiency and less falling into local-minimum. Experimental results show that the proposed technique has good performance in terms of the number of matching blocks, and sum of absolute error for each block, compared with an adjustment of search window using initial set and using adaptive adjustment scheme proposed by [12], when these techniques for search window adjustment are applied for full search(FS), three-step search(TSS), new three-step search(NTSS).

Stimulation of bone formation in the expanding inter-premaxillary suture by vitamin E, in rat

Tancan Uysal,Mihri Amasyali,Huseyin Olmez,Yildirim Karslioglu,Omer Gunhan 대한치과교정학회 2009 대한치과교정학회지 Vol.39 No.5

Objective: The aim of this study was to evaluate the effects of vitamin E (α-tocopherol) administration on bone formation in response to expansion of the inter-premaxillary suture, in rats, histomorphometrically. Methods: Thirty 50 - 60 day old Wistar rats were separated into five equal groups (one control and four experimental). All groups were subjected to inter-premaxilla expansion with 50-gram of force. Six control animals received saline solution (Group I) and three experimental groups were treated with a single dose of α-tocopherol injected into the inter-premaxillary suture after one day after appliance placement (Group II: 2 mg/kg; Group III: 10 mg/kg; and Group IV: 50 mg/kg). A further group of six animals received three injections of 10 mg/kg α-tocopherol, one each on days 3, 6, and 9 (Group V). Bone formation in the suture was evaluated by bone histomorphometry. Kruskal-Wallis rank and Mann-Whitney U tests were used for statistical evaluation at p < 0.05 level. Results: New bone area, bone perimeter, feret?s diameter and newly formed bone measurements were significantly higher in the experimental groups than the control (p < 0.001). Bone architecture in α-tocopherol administrated groups was improved, and bone formation during the expansion period was stimulated significantly, in a dose-dependent manner. Conclusions: The application of α-tocopherol during the early stages to orthopedically expanded inter-premaxillary suture areas may stimulate bone formation and shorten the retention period, in rats. 본 연구는 백서에서 전상악골 봉합부의 확장시 비타민 E (α-토코페롤) 복용의 골형성 효과를 조직계측학적으로 평가하기 위해 시행되었다. 30마리의 50 - 60일된 백서를 6마리씩 5개 집단(대조군과 실험군 4개 집단)으로 분류하였다. 모든 실험 집단에서 50 gm의 힘으로 전상악부를 확장하였다. 장치 장착 1일 후, 대조군(Group I)에는 생리식염수를, 실험군(Group II, Group III, Group IV)에는 α-토코페롤을 각각 2 mg/kg, 10 mg/kg, 50 mg/kg씩 전상악골 봉합부에 주사하였다. 다른 실험군(Group V)에는 장치 장착 3, 6, 9일 후 각각 10 mg/kg씩의 α-토코페롤을 주사하였다. 10일간 유지한 뒤 봉합부에서의 골형성을 조직계측학적 방법으로 평가하였다. Kruskal-Wallis rank 및 Mann-Whitney U test를 사용하여 유의수준 0.05에서 통계분석하였다. 신생골 면적, 둘레, 직경의 계측치에서 실험군이 대조군보다 통계적으로 유의성있게 높은 수치를 나타내었다 (p < 0.001). α-토코페롤을 주사한 집단에서 골 내부구조가 향상되었고, 확장으로 인한골형성은 주사한 α-토코페롤 용량에 비례하여 유의성있게 증가되었다. 백서에서 전상악골 봉합부의 확장시 초기 단계에서의 α-토코페롤 주입은 골형성을 촉진하고 유지기간을 단축시킬 수 있을 것이다.

Stimulation of bone formation by direct electrical current in an orthopedically expanded suture in the rat

Uysal, Tancan,Amasyali, Mihri,Olmez, Huseyin,Karslioglu, Yildirim,Gunhan, Omer The Korean Association Of Orthodontists 2010 대한치과교정학회지 Vol.40 No.2

이 실험적 연구는 직류 전류 자극(direct electrical current stimulation, DECS)을 백서의 확장된 전상악골간 봉합에 가하였을 시 골 재생에 미치는 영향을 평가하기 위해 시행되었다. 60마리의 웅성 Wistar rats를 연구에 사용하였으며 대조군과 실험군의 2개의 군으로 나누었다. 상악 절치 사이에 30-gram의 힘을 발휘하는 helical-spring을 적용하여 상악골의 확장을 두 군 모두에서 시행하였다. 실험군에서는 상악골 측면부에 금속 스크류를 식립하였고 스크류에 전극을 연결하였다. 장치는 지속적으로 $10{\mu}A$의 전류를 흘러 보내도록 조절하였으며 전류는 확장기와 초기 유지기 동안 매일 점검하였다. 골 재생을 조직형태계측학적으로 평가하기 위해 신생골 면적(${\mu}m^2$), 골 둘레길이(${\mu}m$), feret's diameter (${\mu}m$) 와 신생골(%)을 계측하였다. 결과는 유의수준 p < 0.05에서 Kruskal-Wallis rank와 Mann-Whitney U tests를 이용하여 통계 분석하였다. 실험 결과 조사한 모든 조직형태계측적 수치들에서 통계적으로 유의한 차이가 양 군 사이에서 나타났다. 신생골 면적 (p = 0.002), 골 둘레길이 (p = 0.002), feret's diameter (p = 0.002)와 신생골 비율 (p = 0.002)의 모든 계측치가 실험군에서 대조군에 비해 높게 나타났다. 이런 결과는 DECS 군에서 골 형성이 더 양호함을 의미한다. 결론적으로 악정형적으로 확장시킨 전상악골 봉합부에 DECS를 적용하면 초기 유지 기간 중에 신생골 형성이 촉진된다고 할 수 있다. Objective: The aim of this experimental study was to evaluate the effects of direct electrical current stimulation (DECS) on bone regeneration in response to an expansion of the inter-premaxillary suture in the rat. Methods: Sixteen 50 - 60 days old Wistar male rats were separated into two equal groups (control and experimental). Both groups were subjected to expansion, and 30-gram of force was applied to the maxillary incisors with helical-spring. In the experimental group, two metallic-screws were placed at lateral parts of the maxillary segments. Electrodes were connected to the screws. The device was activated with current adjustment to measure $10{\mu}A$ continuously and the current was monitored daily during the expansion and early-retention phase. Bone regeneration in the sutural area was histomorphometrically evaluated including new-bone area (${\mu}m^2$), bone perimeter (${\mu}m$), feret's diameter (${\mu}m$) and newly formed bone (%) parameters. Kruskal-Wallis rank and Mann-Whitney U tests were used for statistical evaluation at p < 0.05 level. Results: Statistical analysis showed significant differences between groups for all investigated histomorphometric parameters. New bone area (p = 0.002), bone perimeter (p = 0.004), feret's diameter (p = 0.002) and newly formed bone percentage (p = 0.002) measurements were significantly higher in the experimental group than the control group. Bone histomorphometric measurements revealed that bone architecture in the DECS group was improved. Conclusions: The application of DECS to an orthopedically expanded inter-premaxillary suture area during the early retention phase stimulated the formation of new bone.

Keratocystic odontogenic tumor: case report with CT and ultrasonography findings

Sumer, A. Pinar,Sumer, Mahmut,Celenk, Peruze,Danaci, Murat,Gunhan, Omer Korean Academy of Oral and Maxillofacial Radiology 2012 Imaging Science in Dentistry Vol.42 No.1

Keratocystic odontogenic tumor (KCOT) is a benign odontogenic tumor with a potentially aggressive and infiltrative behavior. KCOT is most commonly occurred in mandible and demonstrate a unilocular, round, oval, scalloped radiolucent area, while large lesions may appear multilocular. An important characteristic of KCOT is its propensity to grow in an antero-posterior direction within medullary cavity of bone causing minimal expansion. Definitive diagnosis relies on histological examination. In this report, a KCOT that had an expansion both buccal and lingual cortical bone is described including its features in computed tomography and ultrasonographic exams. The lesion was removed surgically via an intraoral approach under local anesthesia and histologically reported as a KCOT.

Hemopericardium and cardiac tamponade in a patient treated with dabigatran etexilate

Filiz Kızılırmak,Haci Murat Gunes,Ekrem Guler,Gultekin Gunhan Demir,Oguz Karaca,Habibe Gamze Canpolat 대한심장학회 2016 Korean Circulation Journal Vol.46 No.1

Dabigatran etexilate is one of the new oral anticoagulants approved to reduce the risk of stroke in patients with atrial fibrillation (AF). A variety of bleeding complications with dabigatran have been reported, but reports of hemopericardium are rare. We described a case of a 66 year-old female patient with non-valvular AF receiving dabigatran etexilate 150 mg twice daily for one year who suffered from hemopericardium. Her laboratory tests performed 1 year prior were normal and her admission tests revealed acute renal failure and elevated international normalized ratio (INR) level (4.79). Urgent pericardiocentesis was followed by improved renal functions and normalized INR. Dabigatran etexilate is a new oral anticoagulant that is increasingly used in daily practice. However, life-threatening complications warrant caution. Elevated INR may be related with overdose but the association of bleeding risk of dabigatran and INR requires further confirmation.

Keratocystic odontogenic tumor : Case report with CT and ultrasonography findings

A. Pinar Sumer,Mahmut Sumer,Peruze Celenk,Murat Danaci,Ömer Gunhan 대한구강악안면방사선학회 2012 Imaging Science in Dentistry Vol.42 No.1

Keratocystic odontogenic tumor (KCOT) is a benign odontogenic tumor with a potentially aggressive and infiltrative behavior. KCOT is most commonly occurred in mandible and demonstrate a unilocular, round, oval, scalloped radiolucent area, while large lesions may appear multilocular. An important characteristic of KCOT is its propensity to grow in an antero-posterior direction within medullary cavity of bone causing minimal expansion. Definitive diagnosis relies on histological examination. In this report, a KCOT that had an expansion both buccal and lingual cortical bone is described including its features in computed tomography and ultrasonographic exams. The lesion was removed surgically via an intraoral approach under local anesthesia and histologically reported as a KCOT.

Tumour Markers in Peritoneal Washing Fluid - Contribution to Cytology

Yildirim, Mustafa,Suren, Dinc,Yildiz, Mustafa,Alikanoglu, Arsenal Sezgin,Kaya, Vildan,Doluoglu, Suleyman Gunhan,Aydin, Ozgur,Yilmaz, Necat,Sezer, Cem,Karaca, Mehmet Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.2

Background: Peritoneal washing cytology (PWC) that shows the microscopic intra-peritoneal spread of gynaecologic cancers is not used in staging but is known as prognostic factor and effective in planning the intensity of the therapy. False negative or false positive results clearly affect the ability to make the best decision for therapy. In this study we assessed levels of tumour markers, carcinoembryonic antigen (CEA), cancer antigen 125 (CA-125) and carbohydrate antigen (CA19-9), in peritoneal washing fluid to establish any possible contribution to the peritoneal washing cytology in patients operated for gynaecologic cancer. Materials and Methods: Preoperative tumour markers were studied in serum of blood samples obtained from the patients for preoperative evaluation of a gynaecologic operation. In the same group peritoneal tumour markers were studied in the washing fluid obtained for intraoperative cytological evaluation. Results: This study included a total of 94 patients, 62 with malignant and 32 with benign histopathology. The sensitivity of the cytological examination was found to be 21% with a specificity of 100%. When evaluated with CEA the sensitivity of the cytological examination has increased to 37%. Conclusions: In addition to examination of PWC, the level of CEA, a tumour marker, in peritoneal washing fluid can make a diagnostic contribution. Determining the level of CEA in peritoneal washing fluid will be useful in the management of gynaecologic cancers.