• Smart Structures and Systems
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• 제32권1호
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• pp.23-35
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• 2023

Steel bolted joint is an important part of steel structure, and its damage directly affects the bearing capacity and durability of steel structure. Currently, the existing research mainly focuses on the identification of corroded bolts and corroded bolts respectively, and there are few studies on multiple states. A detection framework of corroded and loosened bolts is proposed in this study, and the innovations can be summarized as follows: (i) Vision Transformer (ViT) is introduced to replace the third and fourth C3 module of you-only-look-once version 5s (YOLOv5s) algorithm, which increases the attention weights of feature channels and the feature extraction capability. (ii) Three states of the steel bolts are considered, including corroded bolt, bolt missing and clean bolt. (iii) Line segment detector (LSD) is introduced for bolt rotation angle calculation, which realizes bolt looseness detection. The improved YOLOv5s model was validated on the dataset, and the mean average precision (mAP) was increased from 0.902 to 0.952. In terms of a lab-scale joint, the performance of the LSD algorithm and the Hough transform was compared from different perspective angles. The error value of bolt loosening angle of the LSD algorithm is controlled within 1.09%, less than 8.91% of the Hough transform. Furthermore, the proposed framework was applied to fullscale joints of a steel bridge in China. Synthetic images of loosened bolts were successfully identified and the multiple states were well detected. Therefore, the proposed framework can be alternative of monitoring steel bolted joints for management department.

• Steel and Composite Structures
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• 제19권6호
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• pp.1561-1580
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• 2015

No significant improvement has been observed on the seismic performance of the ordinary steel reinforced concrete (SRC) columns compared with the reinforced concrete (RC) columns mainly because I, H or core cross-shaped steel cannot provide sufficient confinement for core concrete. Two improved SRC columns by constructing with new-type section steel were put forward on this background: a cross-shaped steel whose flanges are in contact with concrete cover by extending the geometry of webs, and a rotated cross-shaped steel whose webs coincide with diagonal line of the column's section. The advantages of new-type SRC columns have been proved theoretically and experimentally, while construction measures and seismic behavior remain unclear when the new-type columns are joined onto SRC beams. Seismic behavior of SRC joints with new-type section steel were experimentally investigated by testing 5 specimens subjected to low reversed cyclic loading, mainly including the failure patterns, hysteretic loops, skeleton curves, energy dissipation capacity, strength and stiffness degradation and ductility. Effects of steel shape, load angel and construction measures on seismic behavior of joints were also analyzed. The test results indicate that the new-type joints display shear failure pattern under seismic loading, and steel and concrete of core region could bear larger load and tend to be stable although the specimens are close to failure. The hysteretic curves of new-type joints are plumper whose equivalent viscous damping coefficients and ductility factors are over 0.38 and 3.2 respectively, and this illustrates the energy dissipation capacity and deformation ability of new-type SRC joints are better than that of ordinary ones with shear failure. Bearing capacity and ductility of new-type joints are superior when the diagonal cross-shaped steel is contained and beams are orthogonal to columns, and the two construction measures proposed have little effect on the seismic behavior of joints.

• 구강회복응용과학지
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• 제19권3호
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• pp.153-168
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• 2003

It is very important to arrange the artificial teeth correctly in bucco-lingual (labio- lingual) relation in reconstrcting dentition. Although many anatomic landmarks and techniques have been reported over the years, they are based on westerns. So this study was performd to examine the horizontal relations of mandibular teeth in Korean dentulous adults. 200 volunteers(mean age 22.9) who had natural dentition were selected. The impressions were taken with irreversible hydrocolloid impression material and mandibular study models were fabricated using class I dental stone. Then they were measured with 3-dimensional measuring device specially designed for this study. The results were as follows ; It is better to consider the lingual cusps of the lower posterior teeth as a guide than the linguoaxial surfaces of the lower posterior teeth, arranging the lower posterior teeth buccally to the line which starts from the mesial aspect of the lower canine and continue backward to the lingual aspect of the retromolar pad. It is better to arrange the fossae of the lower posterior teeth buccally to the line which starts from the cusp tip of the lower canine and continue backward to the top of the retromolar pad. The positions of the lower posterior teeth in the denture-bearing area ; considering the fossa as a guide, the 2nd premolar was positioned in center. considering the buccal cusp as a guide, the 1st molar and the 2nd molar were positioned in center. the distance ratio(d/a) was incresed constantly from the lower canine to the 2nd molar d ; the distance between the buccal vestibule(the lowest point) and the buccal cusp tips of the lower posterior teeth. a ; the distance between the buccal vestibule(the lowest point) and the lingual vestibule(the lowest point). The lower canine was positioned lingually($0.11{\pm}0.13$) than the labial vestibule, and the central incisor and the lateral incisor were positioned almost in the imaginary perpendicular plane of the labial vestibule(the lowest point).

• 대한족부족관절학회지
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• 제10권1호
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• pp.56-59
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• 2006

Purpose: The purpose of this study is to find out the normal distal tibial articular surface angle in coronal plane in Koreans. This would be helpful as the basic data for ankle reconstruction after trauma or deformity correction. Materials and Methods: Weight bearing anteroposterior radiographs of 123 normal ankles were reviewed. A line parallel to the shaft of the tibia was made. Another line was drawn parallel to the articular surface of the distal tibia. The superolateral angle that subtended by these two lines was measured. Results: There were 72 males and 51 females. The mean age overall was 35.7 years old. The mean age for males was 31.9 ($28{\sim}36$) years old. The mean age for females was 41.1 ($37{\sim}45$) years old. The mean distal tibial articular surface angle was $90.8^{\circ}$. The mean distal tibial articular surface angle for males was $91.5^{\circ}$ and for females $89.9^{\circ}$. Conclusion: The mean distal tibial articular surface angle in coronal plane for Koreans is $90.8^{\circ}$. We can avoid the error of the varization at the ankle alignment when the correction was performed vertical or minimal valgus to tibia tuberosity axis in Korean people.

• Current Research on Agriculture and Life Sciences
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• 제10권
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• pp.117-123
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• 1992

우수한 재래종(在來種)에 더뎅이병과 역병 저항성(抵抗性) 인자(因子)를 도입(導入)하기 위한품질친(品質親)을 선발(選拔)하기 위하여 '칼미초'에서 선발한 20계통과 '풍각초'에서 선발한24계통을 공시하여 본(本) 대학(大學) 시험포양(試驗圃楊)에 재배(栽培)하여 개화소요일수(開花所要日數), 초장 및 과실특성을 조사(調査)하였다. '칼미초'와 '풍각초' 선발 계통(系統)들은 모두 개화소요일수(開花所要日數)가 많은 만생종(晩生種)이었고, '칼미초' 계통들이 '풍각초' 보다 변이복(變異福)이 더 크게 나타났다. '칼미초'의 일부 계통(系統)들은 초세(草勢)가 강하고 당도(糖度)가 높으며 포양(圃楊)에서 바이러스에 저항성(抵抗性)으로 나타났다. '풍각초'의 일부 계통(系統)은 과종(果種)이 무거운 대과종(大果種)이었으며 과피가 두텁고 제분율(製粉率)이 높게 나타났다. 이상(以上)의 결과(結果)로서 더뎅이병과 역병에 저항성(抵抗性) 품종(品種)을 육성하기 위한 여고잡육종에서 반복친으로 사용할 수 있는 재료(材料)로 '칼미초' 계통 6, 9, 14, 18과 '풍각초' 계통 14, 16, 18등 7계통(系統)을 선발(選拔)하였다.

• 대한한의학회지
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• 제25권4호
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• pp.43-50
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• 2004

Objective : Obesity is associated with degenerative arthropathy giving stress on joints. It also amplifies loads of weight bearing joints by changing the gravity line of the body. Our aim is to investigate the correlation between obesity and lumbar lordosis in obese pre-menopausal Korean females. The hypothesis was tested that there is a correlation between obesity and lumbar lordosis. Methods : A cross-sectional evaluation of 44 Females (baseline age 30.77 ± 6.46) with BMI 31.53 ± 3.82 (kg/㎡) was done. Body composition was measured using bio-impedance analysis (BIA), and anthropometry was done by the same observer. A lateral whole spine X-ray was taken in standing position to measure the lumbar lordotic angle (LLA), Ferguson angle (FA) and lumbar gravity line (LGL). A Pearson correlation was used to measure the correlation between obesity and lumbar lordosis (SPSS 10.0 for windows). Results : Body mass index (BMI kg/㎡) had a negative relationship with LLA((equation omitted)=-0.469), FA((equation omitted) =-0.347) and LGL((equation omitted)=-0.389). Body fat rate had a negative relationship with LLA only(γ=-0.385). Waist circumference had a negative relationship with LLA((equation omitted)=-0.345) and LGL((equation omitted)=-0.346). WH ratio had no relationship with lumbar lordosis. Conclusion : These data show that obesity is related to mechanical structures, such as lumbar lordosis. BMI was the most useful index, which reflects a change of mechanical structure of lumbar, more than other variables in this study.

• 한국임상수의학회지
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• 제30권5호
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• pp.366-370
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• 2013

7개월령 암컷 포메라니안견이 오른쪽 후지 파행 증상으로 내원하였다. 내원시 신체 검사에서 오른쪽 대퇴 관절을 신장하였을 때 통증을 호소하였고 일반 방사선 사진에서 오른쪽 대퇴골두에 미약한 방사선 투과성 병변과 오른쪽 대퇴관절 공간의 확장을 확인하였다. 14일 후 일반 방사선 사진에서 오른쪽 대퇴골두 골단의 변위를 확인하였고 컴퓨터단층촬영에서 오른쪽 대퇴골두에 저음영의 병변과 골절선을 확인하였다. 오른쪽 대퇴골두 절제술을 실시하였고 조직학적 검사에서 골두 골간단과 골단의 괴사를 확인하였다. 본 증례는 초기 허혈성 대퇴골두 괴사증이 있는 개의 방사선학적, 컴퓨터단층촬영, 수술적, 조직학적 소견을 기술하였다.

• 지구물리
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• 제2권2호
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• pp.135-142
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• 1999

선형 자기쌍극자 모델의 하나인 철근에 대하여 3성분 자력계를 이용한 자력검층을 실시한 후 검층자료를 최소 자승법에 의한 역산을 이용하여 해석하였다. 본 실험에 사용된 철근의 길이는 1.12 m, 샘플링 간격은 0.05 m, 자력계와 철근사이의 거리는 0.3 m이며, 철근의 상단부를 깊이 0 m 지점에 고정하였다. 철근은 연직에 가깝도록 위치시켰다. FFT를 이용하여 평활화한 자기이상을 역산의 입력자료로 활용하였다. 검층자료의 해석을 위하여 선형 자기쌍극자의 상단부 심도, 길이, 단위 길이 당 자기모멘트, 자화방향(편각 및 복각), 경사방향과 경사각 등을 미지수로 설정하였다. 자기이상의 수평성분 및 수직성분 각각에 대한 역산 결과와 수평성분과 수직성분을 동시에 고려한 역산 결과를 비교하였는데 각각의 역산결과는 다소 차이를 보인다. 자기이상의 수평성분과 수직성분을 동시에 고려하여 역산을 수행하는 것이 각각의 성분을 역산하는 경우보다 정확한 해석이 가능한 것으로 판단된다. 이 때 철근 하단부의 추정 심도는 1.18 m로, 실제 심도인 1.12 m에 매우 근접하며, 철근의 복각은 -76°로 추정되었다. 철근의 복각이 음(-)의 값을 갖는 것은 철근의 유도자화 강도에 비하여 잔류자화 강도가 훨씬 커서, 전체적인 자화 방향이 철근의 상단 방향을 향하고 있기 때문으로 해석된다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
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• pp.98-98
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• 2003

${\beta}$-(1,3)-D-Glucans have been known to exhibit antitumor and antimicrobial activities. The presence of dectin-1,${\alpha}$, ${\beta}$-glucan receptor of dendritic cell, on macrophage has been controvertial. RT-PCR analysis led to the detection of dectin-1${\alpha}$ and ${\beta}$ in murine macrophage Raw264.7 cell line. Among the various organs of mouse, dectin-1${\alpha}$ and ${\beta}$ were detected in the thymus, lung, spleen, stomach and intestine. To analyze gene expression modulated by ${\beta}$-glucan treated murine Raw264.7 macrophage, total mRNA was applied to cDNA microarray to interrogate the expression of 7,000 known genes. cDNA chip analysis showed that ${\beta}$-glucan of P. osteatus increased gene expressions of immunomodulating genes, membrane antigenic proteins, chemokine ligands, complements, cytokines, various kinases, lectin associated genes and oncogenes in Raw 264.7 cell line. When treated with ${\beta}$-glucan of P. osteatus and LPS, induction of gene expression of TNF-${\alpha}$ and IFN-R1 was confirmed by RT-PCR analysis. Induction of TNF-R type II expression was confirmed by FACS analysis. IL-6 expression was abolished by EDTA in ${\beta}$-glucan and LPS treated Raw264.7 cell line, indicating that ${\beta}$-glucan binds to dectin-l in a Ca$\^$＋＋/ -dependent manner. To increase antitumor efficacy of ${\beta}$-glucan, ginsenoside Rh2 (GRh2) was co-treated with ${\beta}$-glucan in vivo and in vitro tests. IC$\sub$50/ values of GRh2 were 20 and 25 $\mu\textrm{g}$/$m\ell$ in SNU-1 and B16 melanoma F10 cell line, respectively. Co-treatment with ${\beta}$-glucan and GRh2 showed synergistic antitumor activity with cisplatin and mitomycin C both in vitro and in vivo. Single or co-treatment with ${\beta}$-glucan and GRh2 increased tumor bearing mouse life span. Co-treatment with ${\beta}$-glucan and GRh2 showed more increased life span with mitomycin C than that with cisplatin. Antitumor activities were 67% and 72 % by co-injection with ${\beta}$-glucan and GRh2 in the absence or presence of mitomycin C, respectively.

• 자원환경지질
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• 제35권2호
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• pp.155-162
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• 2002

천열수 광상 함금석영맥이 도처에 발달하고 있는 인도네시아 중부 칼리만탄 타란 지역에서 천부 지질정보 획득(지질구조 및 광상분포 확인)을 목적으로 1999년 9월30일부터 10월27일 가지 28일간의 일정으로 자연전위탐사, In-suite 대자율 측정 및 전기 비저항 탐사법를 수행하였다. 자연전위탐사/in-suite 대자율 측정은 10m$\times$250m 간격으로 5개 측선에서, 쌍극자 탐사는 전극간격 ${\alpha}$=30 m, 전극배열 n=7으로 1개 측선에서 행하였다. 탐사결과. 한금 석영맥의 분포지역은 유화광물을 많이 포함하는(은, 아연 및 연의 광화작용)형태, 유화광물을 적게 포함하는(금 광화작용)형태 지역으로 분리 할 수 있다. 측선5에서 낮은 비저항값을 보여주는 구간은 파쇄대, 유화광물을 많이 포함하고 있는 구간을 의미한다.