모르타르 충전식 스플라이스 슬리브의 부착성능에 관한 연구

조승진,안병익,김형기,박복만 明知大學校 産業技術硏究所 2002 産業技術硏究所論文集 Vol.21 No.-

The mechanical joint method is expected to take an important part in the P.C. construction methods. Grout-filled splice sleeve system is used for connecting reinforced concrete column to column and wall to wall in the construction field. This is an experimental study to clarify the bond capacity to be generated between mortar(660kgf/cm2-803kgf/cm2) and reinforcing bar in the grout-filled splice sleeve system. The developed length in the splice sleeve is 4.2d~6.2d Following main conclusions are obtained: (1) Grout-filled splice sleeve system satisfies the structural performance. (2) When comparing the experiment result with existing sleeve design formula on the bond capacity, existing formula is rather safer, but it is considered necessary to present more exact sleeve formula through more close experiment.

수신증이 합병된 복부 방선균증 1례

박무용,김세형,박정훈,이관현,이완복,전진석,김태형 대한감염학회 2004 감염과 화학요법 Vol.36 No.4

Actinomycosis is a chronic suppurative and granulomatous disease caused by Actinomyces species, which normally colonize the mouth, colon, and vagina. Actinomycosis affects any organ and it is histologically characterized by sulfur granule. Most of abdominal actinomycosis develop following appendicitis, diverticulitis or perforated viscus. Abdominal actinomycosis is commonly misdiagnosed as other diseases of intestine because the clinical presentation is non-specific and the radiologic findings mimic tumor. We report a case of abdominal actinomycosis, which initially presented as hydronephrosis and finally diagnosed after laparotomy. Histological findings showed sulfur granules, chronic granulomatous inflammation, and acute inflammatory cells. In our knowledge, this is the first report in Korea of the abdominal actinomycosis associated with appendicitis and complicated with hydronephrosis.

Nerve Growth Factor Stimulates Glioblastoma Proliferation through Notch1 Receptor Signaling

Park, Jun Chul,Chang, In Bok,Ahn, Jun Hyong,Kim, Ji Hee,Song, Joon Ho,Moon, Seung Myung,Park, Young-Han The Korean Neurosurgical Society 2018 Journal of Korean neurosurgical society Vol.61 No.4

Objective : Notch receptors are heterodimeric transmembrane proteins that regulate cell fate, such as differentiation, proliferation, and apoptosis. Dysregulated Notch pathway signaling has been observed in glioblastomas, as well as in other human malignancies. Nerve growth factor (NGF) is essential for cell growth and differentiation in the nervous system. Recent reports suggest that NGF stimulates glioblastoma proliferation. However, the relationship between NGF and Notch1 in glioblastomas remains unknown. Therefore, we investigated expression of Notch1 in a glioblastoma cell line (U87-MG), and examined the relationship between NGF and Notch1 signaling. Methods : We evaluated expression of Notch1 in human glioblastomas and normal brain tissues by immunohistochemical staining. The effect of NGF on glioblastoma cell line (U87-MG) was evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. To evaluate the relationship between NGF and Notch1 signaling, Notch1 and Hes1 expression were evaluated by reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis, respectively. To confirm the effects of NGF on Notch1 signaling, Notch1 and Hes1 small interfering RNAs (siRNAs) were used. Results : In immunohistochemistry, Notch1 expression was higher in glioblastoma than in normal brain tissue. MTT assay showed that NGF stimulates U87-MG cells in a dose-dependent manner. RT-PCR and Western blot analysis demonstrated that Notch1 and Hes1 expression were increased by NGF in a dose-dependent manner. After transfection with Notch1 and Hes1 siRNAs, there was no significant difference between controls and 100 nM $NGF-{\beta}$, which means that U87-MG cell proliferation was suppressed by Notch1 and Hes1 siRNAs. Conclusion : These results indicate that NGF stimulates glioblastoma cell proliferation via Notch1 signaling through Hes 1.

Preparation and Characterisation of CSA-Loaded Nanoemulsion for The Lymphatic Delivery

Hyong-Ju Kim(김형주),Hee-Jung Park(박희정),Yong-Bok Lee(이용복),Ki-Young Lee(이기영) 한국생물공학회 2004 한국생물공학회 학술대회 Vol.2004 No.10

고강도 모르타르 충전식 철근이음의 구조성능에 관한 실험연구

김형기(Hyong-Kee Kim),안병익(Byung-Ik Ahn),남재현(Jae-Hyun Nam),박복만(Bok-Man Park) 한국콘크리트학회 2001 콘크리트학회논문집 Vol.13 No.5

신경망과 k-means 클러스터링을 이용한 사용자의 퍼지값 선호도 학습 방법

윤태복(Tae Bok Yoon),나현종(Hyun Jong Na),박두경(Doo Kyung Park),이지형(Jee Hyong Lee) 한국지능시스템학회 2006 한국지능시스템학회논문지 Vol.16 No.6

퍼지 이론을 이용하면 여러 정보를 통합 요약하기에 수월하여, 웹상에서 사용자에게 제공할 정보를 가공하는 방법으로 많이 사용되고 있다. 하지만 퍼지의 애매모호한 특성 때문에 사용자에게 맞게 퍼지 집합으로 표현된 같은 정보라 하여도 사용자마다 자신의 퍼지값 선호도에 따라 다른 선택을 할 수 있다. 따라서 애매한 퍼지값을 선택함에 있어 사용자의 퍼지값에 대한 선호도를 반영할 필요가 있다. 그러나 기존의 방법들은 정해진 기준을 획일적으로 적용하여, 사용자의 개인적인 선택 기준을 반영하지 못하는 문제가 있다. 본 논문에서는 사용자의 선호도를 학습하여, 사용자의 선호도에 맞는 정보를 선택하는 방법을 제안한다. 사용자의 선호도를 학습하기 위해서 학습 데이터가 필요한데, 이 데이터는 사용자에게 직접 물어 사용자의 선호도를 얻는데 사용된다. 이때, 사용자에게 너무 많은 데이터로 질문을 한다면, 사용자에게 부담을 줄 수 있고, 또 너무 적은 데이터를 사용한다면, 학습을 잘 못하는 경향이 생길 수 있다. 이러한 문제에 대처하기 위해서 10개 정도의 데이터를 이용하여 사용자의 선호도를 학습하는 방법을 제안한다. 제안하는 방법은 먼저 두 퍼지값이 서로 겹칠 수 있는 모든 경우의 상대적 위치를 조사한 후 클러스터링을 이용하여 몇 가지 그룹으로 나누고, 나누어진 그룹을 이용하여 학습하였다. 이렇게 학습된 모델은 새로운 애매하게 겹치는 퍼지값에 대해 사용자를 대신해 어느 것을 어느 정도 선호하는지 추론하게 된다. Fuzzy sets are good for abstracting and unifying information using natural language like terms. However, fuzzy sets embody vagueness and users may have different attitude to the vagueness, each user may choose difference one as the best among several fuzzy values. In this paper, we develop a method learning a user's preference on fuzzy values and select one which fits to his preference. Users' preferences are modeled with artificial neural networks. We gather learning data from users by asking to choose the best from two fuzzy values in several representative cases of comparing two fuzzy sets. In order to establish the representative comparing cases, we enumerate more than 600 cases and cluster them into several groups. Neural networks are trained with the users' answer and the given two fuzzy values in each case. Experiments show that the proposed method produces outputs closer to users' preference than other methods.

그라우트 충전식 철근이음에서 철근의 부착응력도와 슬립 특성에 관한 연구

김형기(Kim Hyong-Kee),박복만(Park Bok-Man) 대한건축학회 2003 大韓建築學會論文集 : 構造系 Vol.19 No.9

In this study, the previous test result of author was analyzed in order to assess the bond stress-slip characteristics between reinforcing bar and grout mortar in splice sleeve. The study result presented in this paper can be helpful in developing more reliable design method for grout-filled splice sleeve.<br/> The followings were found: 1) The remarkable shift of bond stress-slip relationships at the any range between reinforcing bar and mortar appeared, according as the rebar yielded or not. 2) The bond stress between reinforcing bar and mortar in pre-yield regions of rebar was different from that in post-yield regions of rebar. In pre-yield regions of reinforcing bar in splice sleeve, the distribution of bond stress between rebar and mortar was almost uniform along embedded reinforcing bar. Rebar started yielding from the location close to sleeve end. When the rebar yielded in i location, bond stress between i~(i+1) range increased suddenly and the lower bond stress was distributed almost constant in pre-yield regions of reinforcing bar.

압전 페인트 센서를 이용한 복합재 구조물의 충격 신호 감지

박승복 ( Seung Bok Park ),한대현 ( Dae Hyun Han ),강래형 ( Lae Hyong Kang ) 한국복합재료학회 2014 Composites research Vol.27 No.4

본 논문은 충격 센서로써 압전 페인트 센서를 사용해 구조물 건전성 모니터링을 수행하였다. 본 연구에 적용된 압전 페인트는 페인트 형태의 압전 재료로 물체에 얇게 코팅할 수 있고, 추가적인 외부 전원 필요 없이 충격 센서로 사용할 수 있다는 장점을 지닌다. 본 논문에서는 복합재 시편에 압전 페인트 센서를 네 부분으로 구분하여 도포한 후 충격 실험을 수행하였다. 압전 페인트 센서의 감도는 충격 힘에 따른 출력 전압을 측정하여 구하였고, 감도 측정과 더불어, 시편에 충격이 가해진 경우 압전 페인트 센서의 출력 신호를 비교하여 충격 위치도 추정하였다. This paper presents a structural health monitoring method using piezoelectric paint sensor designed for an impact sensor. The piezoelectric paint sensor can be flexibly deposited onto most structural surfaces in a thin form of the paint, and measure impact signals without any external device such as a power amplifier. In this study, a composite plate having four zones coated with piezoelectric paint was used for impact monitoring test. The sensitivity of the piezoelectric paint sensor was obtained by measuring the output voltages against the impact force. In addition to the sensitivity measurement, the impact position has been also estimated by comparing the output signals of the paint sensors when the impact occurs on the specimen.

플랫 플레이트 구조의 기둥ㆍ슬래브 접합부 연성에 관한 연구

김형기(Kim, Hyong-Kee),박복만(Park, Bok-Man) 한국콘크리트학회 2000 콘크리트학회논문집 Vol.12 No.4

구조물의 경계조건에 따른 압전 페인트 센서의 충격검출 특성 평가

박승복(Seung-Bok Park),한대현(Dae-Hyun Han),강래형(Lae-Hyong Kang) 대한기계학회 2014 大韓機械學會論文集A Vol.38 No.12

압전 페인트는 얇은 막의 형태로 선박이나 항공기 등에 도포되어 광범위한 면적에 발생되는 진동이나 충격을 검출하는 데 유용하게 사용될 수 있다. 본 논문은 압전 페인트가 코팅된 구조물에 충격이 가해졌을 경우 충격이 가해진 위치를 검출할 수 있는지 평가해 보고, 다양한 경계 조건에 대해 충격 위치 검출에 차이는 없는지 살펴보았다. 실험에 사용된 압전 페인트 센서는 네 영역으로 알루미늄 시편위에 코팅되었고 분극 과정을 거친 후 한 영역에 충격이 가해졌을 경우 전압의 변화를 실시간 모니터링 하였다. 실험 결과, 충격이 가해진 부분 외 나머지 영역에서는 충격신호의 크기가 매우 작아 충격 신호가 거의 검출되지 않았으며, 경계 조건과 무관하게 모든 조건에서 충격이 가해진 부분에서만 큰 충격신호가 검출되었다. Piezoelectric paint can be used to monitor vibrations or impacts occurring in large engineering structures such as ships and airplanes. This study investigated the impact detection characteristics of a piezoelectric paint sensor and possible errors in detecting impacts according to boundary conditions. The piezoelectric paint sensor used in this study was coated on an aluminum plate with four different electrode areas. After the occurrence of the poling process, the output voltages from the paint sensors were obtained when impact occurred in a certain sensor region. The experimental results revealed a large difference in magnitudes between the sensor signal in the impact region and those in the other regions , and this relation was maintained regardless of the changes in the boundary conditions.