치주질환의 진행정도에 따른 치태세균의 형태적 분석에 관한 연구

안형준,이만섭,권영혁,Ahn, Hyung-Joon,Lee, Man-Sup,Kwon, Young-Kyuk 대한치주과학회 1986 Journal of Periodontal & Implant Science Vol.16 No.1

Lip-Type 모듈형 SC보의 휨내력에 관한 실험적 연구

안형준,신일균,류수현,Ahn, Hyung Joon,Shin, Il Kyoun,Ryu, Soo Hyun 한국강구조학회 2006 韓國鋼構造學會 論文集 Vol.18 No.2

본 논문은 기존의 철근콘크리트의 단점을 개선한 Lip형 모듈단면 MSC보의 휨거동에 대하여 실험값과 이론값을 비교 분석하여 MSC보의 적용에 대한 기초적인자료를 제시하고자하였다. 기존의 SC보는 제작과정에서 절단 및 용접 등 많은 노동력을 필요로 하지만 MSC보는 박판강재를 측면모듈과 하부모듈의 2가지 형태로 모듈화 하여 필요한 크기의 SC보를 손쉽게 제작할 수 있는 프리패브의 개념을 도입하였다. 실험결과 모듈간의 결합방법 및 콘크리트와의 합성방법에 개선이 필요성이 나타났으며 추후 연구를 통해 모듈간의 결합력강화 및 강재와 콘크리트의 합성율을 높인다면 새로운 구조부재로 사용이 가능하다고 판단된다. In this paper, the basic data regarding the application of the MSC (Modular Steel Concrete) beam are presented by comparing the experimental value with the theoretical value, focusing on the bending behavior of the Lip-type MSC beam, which is composed of steel and concrete. Considerable manpower is needed to fabricate the traditional MSC beam, particularly for the tasks of cutting, welding, etc. Because much time is needed to fabricate the traditional SC beam, the prefabrication concept is introduced, easily produce the required size of the SC beam by prefabricating the side module and the lower module, which is made up of a steel sheet. The result indicates that the method of uniting the modules, an d the composition method with concrete, should be improved. The proposed MSC beam can be used as a new structural member by increasing its coherent reinforcement with modules and the composition ratio of steel and concrete through a future study.

실험적 치은염이 치조골 치유에 미치는 영향에 관한 연구

안형준,이만섭,Ahn, Hyung-Joon,Lee, Man-Sup 대한치주과학회 1993 Journal of Periodontal & Implant Science Vol.23 No.3

This study was performed to estimate the effect of plaque control on the progress of the repair pattern of the alveolar bone surface after bone surgery. In this experiment six mongrel dogs were used, four of them were as experimental group and others were as control. In the case of experimental group, dental floss ligature was tied over the neck of crown for permiting of plaque accumulation during one week before surgery and oral hygiene procedures were not performed. In control group, all the surgical intervention was done as same procedure with experimental except oral hygiene program. After surgery plaque was controlled during one week with using the chlorhexidine brushing. Animals were sacrificed at 1,2,4,6 weeks after osseous surgery. The results were as follows : 1. The alveolar bone defects were covered with regenerated epithelium at one week, matrix change of granulation tissue on subcutaneous area was observed, and new bone formation was initiated from the surface of the bone defects. 2. The connective tissue arrangement revealed more dense, new bone formation by osteoblasts was active at 2 weeks and proliferation of gingival epithelium and alveolar bone tissue were evident at 4 weeks, and almostly recovered to normal condition at 6 weeks. 3. In experimental group, inflammatory reaction was persistent in early stage and bone repair was delayed compared to control group. 4. In control group, matrix change of granulation tissue was initiated from one week, regeneration of gingival epithelium and maturation of subcutaneous conective tissue and new bone formation were evident at 2 weeks, so almost normal bone regeneration was observed at 4,6 weeks.

T형 모듈단면 합성 프로파일보의 거동에 관한 실험적 연구

안형준,이성원,류수현,Ahn, Hyung Joon,Lee, Seong Won,Ryu, Soo Hyun 한국강구조학회 2008 韓國鋼構造學會 論文集 Vol.20 No.4

본 연구는 기존에 발표한 T형 모듈단면 프로파일보의 적용가능성을 확인하기 위해 실험체를 제작하고 전단보강 유무에 따른 휨 및 전단거동을 측정하여 그 결과를 소성이론식과 비교 분석하였다. 모듈단면 프로파일보는 프로파일이 거푸집기능에 추가하여 휨 및 전단저항성능에 기여하고 모듈개념을 통해 성형성능을 향상시킨다. 실험결과 전단보강을 실시한 TS계열 실험체가 전단보강이 없는 T계열 실험체에 비해 우수한 휨저항 능력을 나타내 사용된 전단보강재는 적절하게 전단력을 분담하고 있는 것으로 파악되었으나 T1-1실험체를 제외한 모든 실험체에서 볼트의 전단파괴에 의한 모듈간 슬립현상이 발생되어 휨저항 성능이 충분히 발휘되지 못한 것으로 판단된다. 추후 전단연결재를 변수로 한 T형 모듈단면 프로파일보에 관한 연구를 통해 적절한 모듈간 접합방법이 연구 되어져야 할 것으로 판단된다. This study aims to determine the applicability of the previously published T-type modular profile beam in the manner of producing specimens designed specially for the said purpose, determining their bending and shear behaviors depending on the presence of shear reinforcement, and analyzing the results in comparison with the theoretical equation of plastic deformation. The modular profile beam contributes to bending and shear resistance with the addition of the profile to the form function, and enhances the molding performance through the modular concept. The experimental results showed that the TS series specimens with shear reinforcement have bending behaviors superior to those of the T series specimens without shear reinforcement, which suggests that the used shear reinforcement appropriately bears the shear force. However, it was considered that all the specimens except for the T1-1 specimen failed to have adequate bending performance because of the intermodular slipping caused by the shear failure of the bolts. It is expected that further studies on the T-type modular profile beam, in which shear connectors will be considered as a variable,be performed to develop optimal intermodular connection methods.

증령적 변화로서의 두개골 봉합의 유합 상태

안형준,신경진,권정승,도형주,최종훈,김종열,Ahn, Hyoung-Joon,Sin, Kyoung-Jin,Kwon, Jeong-Seung,Do, Hyung-Joo,Choi, Jong-Hoon,Kim, Chong-Youl 대한안면통증구강내과학회 2001 Journal of Oral Medicine and Pain Vol.26 No.4

In order to study the closure stage of cranial sutures and its correlations with age, the ectocranial closure stage of coronal suture, sagittal suture, and lambdoidal suture of 67 skulls was measured. Among the skulls kept at the department of anatomy, college of medicine, Yonsei University, the ones with ages identified were used for this study. These measurements of suture closure were conducted by 4 examiners independently. The sutures were further divided by Frederic's method into 16 suture parts. The closure stages were classified by five stages of Broca-Ribbe. The following results were obtained: 1. The inter-observer reliability among 4 examiners showed high intraclass correlation coefficient of over 0.75(mean : 0.856) in all suture parts. Therefore, the determination of closure stage wasn't influenced by the subjective view of each examiner. 2. In all suture parts, the closure stage increased proportionally with age.(p<0.01) In terms of each suture part, the S2 part of sagittal suture showed the highest correlation(68.1%) while the L1-R part of lambdoidal suture showed the lowest correlation(51.3%). In addition, in terms of suture types, the correlation with age decreased in the order of sagittal suture(60.0%), coronal suture(57.7%), and lambdoidal suture (55.7%). In general, the average value of suture closure stages had 57.8% correlation with age(p<0.01). 3. The most frequent suture closure stage according to age group was '0' for ages below 30, '0' and '1' for ages within the 30's, '1' and '2' for ages within the 40's, and '2' for ages within the 50's. With older age groups, the frequency of '3' and '4' increased, and the suture closure stage increased proportionally with age. 4. The mean age by closure stage of each suture were within the 40's for the closure stage of '1', within the 50's for the closure stage of '2', and from 50's through 60's for the closure stage of '3'. The standard deviation was over 10 for all closure stages. In addition, at the same suture closure stage, the mean age according to the coronal suture was higher than the ages according to the sagittal suture or lambdoidal suture. Especially, C1-R, C1-L, C2-R, and C2-L parts showed the highest age when at the same suture closure stage. 5. The values appropriate for age estimations using suture closure stages of 16 suture parts were calculated, and a calculator for age estimation ($R^2=0.6944$, p<0.01) by ectocranial suture closure stage for Koreans is presented. From the above results, the method of using the closure stage of sutures of the skull to estimate age can be useful in individual identification of forensic science. Further extensive and accurate research using larger samples would be worthy of study.

BESTOBEAM 전단연결재의 길이에 따른 전단 내력 평가

안형준,정인용,김영주,황재선,Ahn, Hyung Joon,Jung, In Yong,Kim, Young Ju,Hwang, Jae Sun 한국강구조학회 2015 韓國鋼構造學會 論文集 Vol.27 No.5

앵글을 전단연결재로 사용한 시공개선형 합성보(BESTOBEAM)의 전단연결재 길이에 따른 전단 내력을 실험적으로 평가하고 전단내력 설계식을 제안하였다. Eurocode 4의 경우와 달리 BESTOBEAM의 전단연결재는 등분포 하중을 받는 보의 거동과 유사하며 그 순경간(BESTO Width)에 따라 전단 내력이 달라진다. BESTO Width와 콘크리트의 강도에 따른 전단 내력을 Push-out 실험을 통해 측정한 결과 BESTO Width가 길어질수록 내력이 감소하고 연성능력은 증가하는 경향을 보였다. 실험결과를 반영하여 Eurocode 4의 설계식을 수정하여 새로운 설계식을 제안하였다. 제안된 설계식을 통해 예측된 전단연결재의 강도는 10% 오차 범위 이내로 잘 맞는 것을 확인할 수 있었다. 따라서 앵글을 전단연결재로 사용한 BESTOBEAM의 전단 강도 설계에 제안된 식을 사용할 수 있을 것으로 판단된다. Shear resistance of BESTOBEAM, which has angle as shear connector and was developed with purpose of easy construction, was tested. With the test results shear resistance design equation was proposed. Unlike angle connector of Eurocode 4, BESTO BEMA shear connector behaves like fixed-end beam. Therefor longer span of the shear connector the lower shear resistance it has. As a result, shear resistance of BESTOBEAM shear connector according to its length tends to decrease as its length gets longer. The authors proposed design equation of angle shear connector sased on the test results. The results from the test and the proposed equation match within 10% error range. Therefore the proposed equation can be used for designing shear connector of BESTOBEAM.

치주질환에 대한 Argon 레이저의 효과

안형준,유지원,김재홍,김종열,Ahn, Hyung-Joon,Ryu, Ji-Won,Kim, Jae-Hong,Kim, Chong-Youl 대한안면통증구강내과학회 2005 Journal of Oral Medicine and Pain Vol.30 No.2

The purpose of this study was to evaluate photothermal effect of laser, which eliminates and reduces bacteria causing periodontal disease, on treatment of periodontal disease. This study included subjects with moderate periodontitis who visited the Department of Oral Medicine, College of dentistry, Yonsei University. The subjects were divided into experimental group, where Argon laser treatment was used, and control group, where conventional subgingival curettage was used. Gingival fluids from each subject were collected prior and after 1 week of the treatment, and changes in number of bacterial colonies cultured from aerobic as well as anaerobic bacteria responsible for the periodontal disease, and changes in clinical indices related to the periodontal disease, such as plaque index, gingival index, sulcus bleeding index, were analysed. As a result, the number of bacterial colonies of aerobic and anaerobic bacteria reduced after 1 week of the treatment in both groups, especially the bacterial colonies of anaerobic bacteria which showed statistically significant reduction(p<0.1). However, there was no significant difference between the experimental group and the control group. Clinical indices including plaque index, gingival index, sulcus bleeding index were reduced after 1 week of the treatment in both groups. In the experimental group, gingival index(p<0.1) and sulcus bleeding index(p<0.01) showed significant reduction, and, in the control group, sulcus bleeding index(p<0.01) showed significant reduction. However, there were no significant differences in each indices between the two groups. The above results suggest that Argon laser could be used as a substitute of conventional subgingival curettage, or in combination with subgingival curettage which would increase the effect of the treatment. Although the possibility of clinical application of Argon laser was observed in this study, more randomized-controlled research, including acquirement of sufficient samples as well as long-termed follow up, would be necessary before clinically effective application of Argon laser.

Inner Bolted Type 의 각형강관기둥-End Plate 접합부의 최대내력

안형준(Hyung Joon Ahn),오영석(Young Suk Oh),문태섭(Tae Sup Moon) 한국강구조학회 1992 韓國鋼構造學會誌 Vol.4 No.2

Developing a new type of H beam to SHS column resisting connection which has sufficient strength, rigidity and ductility as well is the objective of this research. This connection is a kind of end-plated, of the maximum strength are made by means of the yield line theory. They are compared with experimental values and the optimum proportioning of this connection system which can exhibit the reasonable strength is suggested.

각형강관기둥-H형강보 접합부에 관한 실험적 연구

안형준(Hyung Joon Ahn),문태섭(Tae Sup Moon) 한국강구조학회 1992 韓國鋼構造學會誌 Vol.4 No.3

This study aims at applying cold-formed square hollow section members to high rise building for high rise steel structure system adaptable to Korean circumstance in the point of load capacity and construction availablity by beam- to-column connection composed of H-section beam and cold-formed square hollow section column. Based on this investigation of the test result, we are to acquire report, detail design of beam-to-column connection according to new beam-to-column connection system used cold-formed square hollow section members.

T형 모듈 단면 프로파일보의 휨내력에 관한 연구

안형준(Ahn Hyung-Joon),이성원(Lee Sung-Won),류수현(Ryu Soo-Hyun) 대한건축학회 2008 大韓建築學會論文集 : 構造系 Vol.24 No.1

This study was attempted to make a study of the bending behavior of T-section Modular Composite Profile Beams(TMPB), which is characterized by mass production, less construction period, and cost saving of the module, by modular assembly of the cross section through experiments and on the basis of the theory, and to look into the applicability of major parameters by changing thickness of the lower module mostly being under tension. As results of the experiments, T1-1 sample where thickness of the upper module and the lower module was same displayed fully combined plastic behavior of the modules, which indicates the good performance of TMPB by thin film profile. For T1-2 sample where a thickness ratio between the upper module and the lower module was 2, the rate between experimental value and theoretical value was 79%, thus it is deemed applicable. On the other hand, for T1-3 and T1-4 samples where a thickness ratio between the upper module and the lower module was large, the rate between experimental value and theoretical value was 50% or so, which indicates that it did not fully display plastic behavior. Putting initial stiffness, ductility and strength together, it is deemed that TMPB can be fully applicable as long as a thickness ratio of the upper and lower modules is 2 or less, and that further studies on shear reinforcing method are necessary.