• 치과방사선
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• 제29권1호
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• pp.209-221
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• 1999

Purpose: The purpose of this study was to calculate the size and CT number of both normal parotid and submandibular gland. and evaluate their relation to sex, age and obesity using computed tomography. Materials and Methods: The computed tomography was performed parallel to the Frankfurt plane in 46 subjects with healthy salivary gland. The subjects were divided into the three groups (young, middle. old) according to their ages. The size of salivary gland was determined as maximum cross-sectional area and the CT number of salivary gland was determined as the mean CT number of three ROI's. The body mass index was calculated from weight and height. Results: The mean maximum cross-sectional area was 7.79(±1.25)cm² on parotid gland and 4.12(±0.83) cm² on submandibular gland. The mean CT number was -4.43(±23.87) HU on parotid gland and 50.01(±15.63) HU on submandibular gland. There was decreasing pattern of the maximum cross-sectional area of submandibular gland and the CT number of both parotid and submandibular gland according to age(p<0.05). As the body mass index increased. the maximum cross-sectional area of parotid gland increased and CT number of both parotid and submandibular gland decreased(p<0.05). The maximum cross-sectional area of submandibular gland in male was larger than that in female(p<0.05). As the maximum cross-sectional area and CT number of left salivary gland increased. those of right gland increased(p<0.05). Conclusion : Intra-individual differences in salivary gland size and CT number is considered in the age and individual obesity.

• 대한의용생체공학회:의공학회지
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• 제16권2호
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• pp.149-156
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• 1995

동맥전단부를 연구할수있는 새로운 실험방법과 기계역학적 분석방법을 제시하였다. 지금까지동맥역학적 연구는 대부분이 동맥의 길이방향과 원주방향에 대한것이 이였다. 두께방향의 변형은 포아손비라든지 비압축성가정으로 이론적으로 결정되었다. 또한 두께에 걸친 변형의 변화도 무시되었다. 그러나 병리학적인 의미에서 동맥의 두께에 걸친 변형도와 변형의 분포는 중요한 의미를 가진다. 그러므로 본연구에서 제안된 실험방법과 장치는 두께전반에 걸친 변형을 측정할수 있게 했다. 또한 전단부의 부위별 변형도의 관찰이 가능하고 병리적인 동맥경화증에 대한 현상과 역학적현상을 상관시킬 수 있음에 중요한 의미를 들 수 있다.

• Steel and Composite Structures
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• 제19권3호
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• pp.661-678
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• 2015

Buckling Restrained Braces (BRB) have been widely used in the construction industry as they utilize the most desirable properties of both constituent materials, i.e., steel and concrete. They present excellent structural qualities such as high load bearing capacity, ductility, energy-absorption capability and good structural fire behaviour. The effects of size and type of filler material in the existed gap at the steel core-concrete interface as well as the element's cross sectional shape, on BRB's fire resistance capacity was investigated in this paper. A nonlinear sequentially-coupled thermal-stress three-dimensional model was presented and validated by experimental results. Variation of the samples was described by three groups containing, the steel cores with the same cross section areas and equal yield strength but different materials (metal and concrete) and sizes for the gap. Responses in terms of temperature distribution, critical temperature, heating elapsed time and contraction level of BRB element were examined. The study showed that the superior fire performance of BRB was obtained by altering the filler material in the gap from metal to concrete as well as by increasing the size of the gap. Also, cylindrical BRB performed better under fire conditions compared to the rectangular cross section.

• 치과방사선
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• 제27권1호
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• pp.7-16
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• 1997

This study was performed to demonstrate the method of image reformation for dental implants, using a personal computer with inexpensive softwares and to compare the images reformatted using the above method with those using Dentascan software. CT axial slices of 5 mandibles of 5 volunteers from GE Highspeed Advantage(GE Medical systems, U.S.A.) were used. Personal computer used for image reformation was PowerWave 6041120 (Power Computing Co, U.S.A.) and softwares used were Osiris (Univ. Hospital of Geneva, Switzerland) and Import ACCESS V1.H Designed Access Co., U.S.A.) for importing CT images and NIH Image 1.58 (NIH, U.S.A.) for image processing. Seven images were selected among the serial reconstructed cross-sectional images produced by Dentascan(DS group). Seven resliced cross-sectional images at the same position were obtained at the personal computer(PC group). Regression analysis of the measurements of PC group was done against those of DS group. Measurements of the bone height and width at the reformed cross-sectional images using Mac-compatible computer were highly correlated with those using workstation with Dentascan software(height : r²=0.999, p<0.001, width : r²=0.991, p<0.001). So, it is considered that we can use a personal computer with inexpensive softwares for the dental implant planning, instead of the expensive software and workstation.

• 한국조사연구학회지:조사연구
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• 제12권3호
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• pp.173-186
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• 2011

본 연구에서는 2003년 시작된 한국청소년패널조사 중학교 2학년 패널자료 분석을 위해 필수적인 각 연도별 횡단면, 종단면 가중치 산출방안을 소개하고 있다. 패널 모집 당시 추출된 표본이 대표하는 모집단의 종단면적 변화 분석을 위한 종단면 가중치는 로지스틱 회귀분석을 이용한 무응답 보정과 사후 층화를 통해 산출되었으며, 조사 연도의 표본 대응 모집단 분석을 위해 필수적인 횡단면 가중치는 전년도 대비 응답률과 사후 층화를 통해 산출되었다.

• Journal of Oral Medicine and Pain
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• 제21권2호
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• pp.255-264
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• 1996

This study was performed to demonstrate the method of image reformation for dental implants, using a personal computer with inexpensive softwares and to compare the images reformatted using the above method with those using Dentascan software. CT axial slices of 4 mandibles of 4 volunteers from GE Highspeed Advantage(GE Medical systems, U.S.A.) were used. personal computer used for image reformation was PowerWave 604/120 (Power computing Co, U.S.A. ) and softwares used were Osiris (Univ. Hospital of Geneva, Switzerland) and ImportACLESS Vl.1 (Designed Access Co., U.S.A.) for importing CT images and NIH image 1.58 (NIH, U.S.A.) for image processing. Seven image were selected among the serial reconstructed cross-sectional images produced by Dentascan. Seven resliced cross-sectional images at the same position were obtained at the personal computer. Regression analysis of the measurements of PC group was done against those of DS group. Measurements of the bone height and width at the reformer cross-sectional images using Mac-compatible computer was highly correlated with those using workstation with Dentascan software(height : r2= 0.999, p<0.001, width : r2= 0.993, p <0.001). So, it is considered that we can use a personal computer with inexpensive software for the dental implant planning, instead of the expensive software and workstation.

• Advances in Computational Design
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• 제6권1호
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• pp.31-42
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• 2021

This research aims to demonstrate the optimal geometrical design of splayed multiple cross-sectional pin fin heat sinks (SMCSPFHS), which are a type of side-inlet-side-outlet heat sink (SISOHS). The optimiser strength Pareto evolutionary algorithm2 (SPEA2)is employed to explore a set of Pareto optimalsolutions. Objective functions are the fan pumping power and junction temperature. Function evaluations can be accomplished using computational fluid dynamics(CFD) analysis. Design variablesinclude pin cross-sectional areas, the number of fins, fin pitch, thickness of heatsink base, inlet air speed, fin heights, and fin orientations with respect to the base. Design constraints are defined in such a way as to make a heat sink usable and easy to manufacture. The optimum results obtained from SPEA2 are compared with the straight pin fin design results obtained from hybrid population-based incremental learning and differential evolution (PBIL-DE), SPEA2, and an unrestricted population size evolutionary multiobjective optimisation algorithm (UPSEMOA). The results indicate that the splayed pin-fin design using SPEA2 issuperiorto those reported in the literature.

• The Journal of Korean Physical Therapy
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• 제26권5호
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• pp.324-330
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• 2014

Purpose: The aim of the current study was to compare the muscle architecture of lower extremity using rehabilitative ultrasound imaging (RUSI) in young adults in Seoul and Hanoi. Methods: The study design was a comparative study of muscle cross-sectional area of lower extremity. Sixty healthy young subjects (Seoul group: 30, Hanoi group: 30) participated in this study. Real-time B-mode RUSI with a 7.5MHz linear transducer was used for measurement of cross-sectional area, pennation angle, and muscle thickness of the rectus femoris, tibialis anterior, and medial gastrocnemius muscles. Independent t-test was used for statistical analysis. Results: Significant difference in cross sectional area of rectus femoris was observed between Korean young adults and Hanoi young adults (p<0.01). Muscle thickness and pennation angle of tibialis anterior in Korean young adults were greater than in Hanoi young adults (p<0.01). In addition, the muscle thickness and pennation angle of the medial part of gastrocnemius muscle were greater in Korean young adults than in Hanoi young adults (p<0.01). In addition, in the results for gender, men had larger muscle architectures than women in both groups (p<0.01). Conclusion: This study, using RUSI, showed significant difference in muscle architectures of lower extremity in a diverse group of young adults RUSI.

• 한국생산제조학회지
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• 제26권3호
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• pp.337-343
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• 2017

The laser cladding process on structural steel (SCM440) and gray cast iron (GC250) substrates with Co-based powder (Stellite 12) was studied. A diode laser (2 kW) was used as a heat source, and the powder was supplied by a disc rotary powder feeder. The relationship between the laser cladding process and the cross-sectional analysis of coating was examined based on coating shape and microstructure. Additionally, the microhardness was measured to confirm the mechanical property improvements. As a result, proper laser cladding conditions were selected through this study and verified by cross-sectional analysis. In addition, the evaluation process for laser cladding feasibility was conducted on the selected materials.

• 한국철도학회논문집
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• 제9권3호
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• pp.251-256
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• 2006

This paper explains manufacturing process, analysis and experimental studies on a hybrid composite carbody of Korean tilting train. The composite carbody with length of 23m was manufactured as a sandwich structure composed of a aluminium honeycomb core and woven fabric carbon/epoxy faces. In order to evaluate deformational behavior of the composite carbody, the static load test under vertical load has been conducted. From the test, the vertical deflection an겨 cross sectional deformation of the carbody were analysed and measured. The maximum deflection along the side sill was 9.25mm in the experiment and 8.28mm in the analysis. The maximum cross sectional deformation was measured 5.42mm at carbody center in lateral direction and 4.06mm at roof center in vertical direction.