• 한국의류산업학회지
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• 제14권6호
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• pp.968-976
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• 2012

This study presents a new method called the SPMP (Semi-automatic profile measuring program) to efficiently measure body shape in elderly women. SPMP can automatically measure the angle of axis (19 items), surface (17 items), lengths (14 items), heights (16 items), widths (13 items), and depth (6 items). In total these 85 items are automatically measured very quickly, accurately, and easily after manually marking an initial 36 points. The utility of SPMP was evaluated using several tests. When SPMP measuring results were compared with manual methods (using a ruler and protractor) in thirteen elderly women using a paired t-test, there was no significant difference found between them. Furthermore, when measurements from SPMP were compared with actual measurement results in selected items from seven elderly women's measurements, smaller mean differences were found than those defined by ISO 20685, with the exception of the abdominal area which moves easily with breathing. Seven independent measurements of a single elderly woman were made by seven students using SPMP, and the values of coefficient of variation were less than 5% for all but 8 items. Finally, this study analyzed the correlation of all 85 item measurements, and found that the angle from the upper chest to the neck towards the front in the axis curved forward as much as the axis angle from the thigh to the waist (r=-0.876, $^{**}p$ < 0.01) bent backwards in elderly women. This detailed analysis helps to understand age-related changes in body posture, and will be useful in future studies.

• 천문학회보
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• 제46권2호
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• pp.76.3-77
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• 2021

GMT secondary mirror system consists of 7 segmented adaptive mirrors. Each segment consists of a thin shell mirror, actuators and a reference body. The thin shell has a few millimeters of thickness so that it can be easily bent by push and pull force of actuators to compensate the wavefront disturbance of light due to air turbulence. The one end of actuator is supported by the reference body and the other end is adapted to this thin shell. One of critical role of the reference body is to provide the reference surface for the thin shell actuators. Therefore, the reference body is one of key components to succeed in development of GMT ASM. Recently, Korea Research Institute of Standards and Science (KRISS) and University of Arizona (UA) has signed a contract that they will cooperate to develop the first set of off-axis reference body for GMT ASM. This project started August 2021 and will be finished in Dec. 2022. The reference body has total 675 holes to accommodate actuators and 144 pockets for lightweighting. The rear surface has a curved rib shape with radius of curvature of 4387 mm with offset of 128.32mm. Since this reference body is placed just above the thin shell so that the front surface shape needs to be close to that of thin shell. The front surface has a concave off-axis asphere, of which radius of curvature is 4165.99 mm and off-axis distance is about 1088 mm. The material is Zerodur CTE class 1 (CTE=0.05 ppm/oC) from SCHOTT. All the actuator holes and pockets are machined normal to the front surface. It is a very complex challenging optical elements that involves sophisticated machining process as well as accurate metrology. After finishing the fabrication of reference body in KRISS, it will be shipped to UA for final touches and finally sent to Adoptica in Italy, in early 2023. This paper presets the development plan for the GMT ASM Reference Body and relevant fabrication and metrology plans.

• Structural Engineering and Mechanics
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• 제26권3호
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• pp.343-361
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• 2007

This article presents a numerical tool for dimensioning two-threaded fasteners connecting prismatic parts subjected to fatigue tension loads that are coplanar with the screw axis. A simplified numerical model is developed from unidirectional finite elements, modeling the connected parts and screws with bent elements and the elastic contact layer between the parts with springs. An algorithm updating the contact stiffness matrix, calculating forces and displacements at each node of the structure and thus normal stresses in the screws in both static and fatigue is further developed using C language. An experimental study is also conducted in parallel with the numerical approach to validate the developed model assumptions, the numerical model and the 3D finite element results. Since stiffness values for the compressive zones in the parts are analytically difficult to determine, a statistical software method is used, from which a tuning factor is derived for identifying these stiffness values. The method is also applied to set out the influence of each parameter on the fatigue behaviour of each screw. Finally, the developed model will be used to establish a new, sophisticated, fast and accurate tool for dimensioning bolted mechanical structures.

• 제어로봇시스템학회논문지
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• 제4권3호
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• pp.384-391
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• 1998

When a device is mounted on the PCB, it is impossible to have zero defects due to many unpredictable problems. Among these problems, devices with bent corner leads due to mis-handling and which are not placed at a given point measured along the axis are principal problem in SMT(Surface Mounting Technology). It is obvious that given the complexity of the inspection task, the efficiency of a human inspection is questionable. Thus, new technologies for inspection of SMD(Surface Mounting Device) should be explored. An example of such technologies is the Automated Visual Inspection(AVI), wherein the vision system plays a key role to correct this problem. In implementing vision system, high-speed and high-precision are indispensable for practical purposes. In this paper, a new algorithm based on the Radon transform which uses a projection technique to inspect the FIC(Flat Integrated Circuit) device is proposed. The proposed algorithm is compared with other algorithms by measuring the position error(center and angle) and the processing time for the device image, characterized by line scan camera.

• Steel and Composite Structures
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• 제30권5호
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• pp.471-481
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• 2019

Beam-columns are structural members subjected to a combination of axial and bending forces. Lateral-torsional buckling is one of the main failure modes. Beam-columns that are bent about its strong axis may buckle out of the plane by deflecting laterally and twisting as the values of the applied loads reach a limiting state. Lateral-torsional buckling failure occurs suddenly in beam-column elements with a much greater in-plane bending stiffness than torsional or lateral bending stiffness. This study intends to establish a unique convenient closed-form equation that it can be used for calculating critical elastic lateral-torsional buckling load of beam-column in the presence of a known axial load. The presented equation includes first order bending distribution, the position of the loads acting transversely on the beam-column and mono-symmetry property of the section. Effects of axial loads, slenderness and load positions on lateral torsional buckling behavior of beam-columns are investigated. The proposed solutions are compared to finite element simulations where thin-walled shell elements including warping are used. Good agreement between the analytical and the numerical solutions is demonstrated. It is found out that the lateral-torsional buckling load of beam-columns with mono-symmetric sections can be determined by the presented equation and can be safely used in design procedures.

• Bulletin of the Korean Chemical Society
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• 제26권11호
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• pp.1728-1734
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• 2005

The interactions of Cu(II)-meso-Tetrakis(n-N-methylpyridiniumyl)porphyrin (n = 2,3,4), respectively referred to as o-, m- and p-CuTMPyP, and DNA, poly$[d(A-T)_2]$ and poly$[d(G-C)_2]$ were investigated by circular and linear dichroism (CD and LD). In the o-CuTMPyP case, in which the rotation of the pyridinium ring is prevented, the shape of the CD spectrum when associated to DNA and poly$[d(A-T)_2]$ resembles and is characterized by a positive band at a low drug to DNA concentration ratio (R ratio) and is bisignate at a high R ratio. The former CD spectrum shape has been attributed to porphyrin that is bound monomerically outside of DNA while the latter can be attributed to those that are stacked. When o-CuTMPyP is bound to poly$[d(G-C)_2]$, the excitonic CD appeared at a relatively high R ratio. In contrast, a characteristic negative CD band in the Soret region was apparent for both m- and p-CuTMPyP when bound to DNA and poly$[d(G-C)_2]$ at the low R ratios, indicating that the porphyrin molecule intercalates. However, the DNA is bent near the intercalation site and the plane of the porphyrin molecule tilts relative to the DNA helix axis, as judged by the magnitude of the reduced LD. Various stacking patterns were identified by the shape of the CD spectrum for m- and p-CuTMPyP when bound to poly$[d(A-T)_2]$. Three species for the former complex and two for the latter complex were found which may reflect the extent of the stacking.

• 한국결정학회지
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• 제17권1호
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• pp.6-9
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• 2006

Bis(N-Methylphenazinium)-Tetracyanopalladate(II) Hydrate $(C_{13}H_{11}N_2){_2}[Pd(CN)_4]{\cdot}H_2O$의 단위 착이온 및 결정의 구조들을 X-선 회절법으로 연구하였다. 이 결정은 사방정계이고 공간군은 $P2_1/b$(군번호=14)이다. 단위세포 a=9.783(4), b=10.788(4), c=13.666(4) ${\AA},\;{\beta}=104.59(5),\;V=1392.9{\AA}{^3},\;Z=2,\;Dc=1.476gcm^{-3},\;F(000)=632,\;{\mu}=7.05cm^{-1}$이다. 구조분석은 중금속법으로 풀었으며, 최소자승법으로 정밀화 하였고, 최종 신뢰도 값들은 1930 회절반점에 대하여 R=0.0257, Rw=0.0732, Rall=0.0283 및 S=1.07 이었다. 두 이온들은 근본적인 평면구조로써, 이들의 충진구조는 착음이온을 두개의 양이온들이 거의 평행하게 둘러싸고 있는 삼중체들을 형성하고 있다. 양이온과 음이온들의 이면각은 $10.16(4)^{\circ}$인 삼중체들이 b축을 따라서 배열되어 있다, 삼중체내 및 삼면체간의 면간 거리들은 3.419(3)와 $3.402(4){\AA}$이었다.

• Tribology and Lubricants
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• 제30권4호
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• pp.218-223
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• 2014

This paper presents a method of controlling the stiffness of a tungsten probe for an atomic force microscope (AFM) in order to provide high-quality phase contrast images in accordance with sample characteristics. While inducing sufficient deformation on sample surfaces with commercial Si or $Si_3N_4$ probes is difficult because of their low stiffness, a tungsten probe fabricated by electrochemical etching with appropriately high stiffness can generate relatively large elastic deformation without damaging sample surfaces. The fabrication of the tungsten probe involves two separate procedures. The first procedure involves immersing a tungsten wire with both ends bent parallel to the surface of an electrolyte and controlling the stiffness of the tungsten cantilever by decreasing its diameter using electrochemical etching in the direction of the central axis. The second procedure involves immersing the end of the etched tungsten cantilever in the direction perpendicular to the surface of the electrolyte and fabricating a tungsten tip with a tip radius of 20-50 nm via the necking phenomenon. The latter etching process applies pulse waves every 0.25 seconds to the manufactured tip to improve its yield. Finite element analysis (FEA) of the stiffness of the tungsten probe as a function of its diameter showed that the stiffness of the tungsten probes greatly varies from 56 N/m to 3501 N/m according to the cantilever diameters from $30{\mu}m$ to $100{\mu}m$, respectively. Thus, the proposed etching method is effective for producing a tungsten probe having specific stiffness for optimal use with an AFM and certain samples.

• 대한의용생체공학회:의공학회지
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• 제16권4호
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• pp.481-491
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• 1995

Endovaginal and endorectal receiver only surface coils were designed for MR imaging (MRI) and $^1H$ MR spectroscopy (MRS) for the uterine cervix and the prostate. The shape of endovaginal coil wire was rectangular with round corner. Size of the coil wire was empirically determined for 7cm and 4cm along the long and short axis, respectively. The coil wire loop was supported by acryl handle and bent about $150^{\circ}$ at one side of the loop considering the average angle of the cervix to the vagina. We called this as a "spoon-type endovaginal coil". The wire of the endorectal coil was made of the flexible materials so that the wire loop became long elliptic shape by pushing the acryl handle into the plastic tube for the comfort of patients when the coil was inserted into the cervix. Then, the shape was maintained to be circle by popping out handle. Conventional spin echo (SE) and fast spin echo (FSE) sequences were used as 71 and 72 weighted imaging sequences, respectively. Matrix size was 128~$256{\times}256$. FOVs for surface coil and body coil were 14cm and 24cm, respectively. 3D volume localized in vivo $^1H$ MR spectroscopy of the human cervix and prostate was performed using PRESS or STEAM localization method with the following parameters . TR=3 sec, TE=135 msec for PRESS or 30 msec for STEAM, NEX=2, NS=48, Sl=2048, and SW=2500 Hz. Using home-built endovaginal and endorectal coils, excellent T1- and T2-images were obtained to visualize early cervical and prostate tumors. 3D volume localized in vivo IH MRS was useful to differentiate the cancerous tissue from the normal tissue.

• 한국어류학회지
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• 제25권4호
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• pp.239-243
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• 2013

경남 통영과 거제에서 실고기과 어류 2개체가 채집되었다. 한국에서는 미기록종인 Syngnathoides biaculeatus로 동정되었고, 본종이 포함되는 속(Syngnathoides) 역시 한국 미기록으로 확인되었다. 본 종의 형태는 긴 형태를 띠며, 체륜상 골판으로 덮여 있다. 몸통부는 두부와 꼬리부보다 굵으며, 두부와 몸통은 일자형이다. 주둥이는 긴 관모양이며, 눈 후연에서 아가미 후연까지의 길이보다 길다. 등지느러미는 몸의 뒤쪽에 위치하고, 매우 작은 뒷지느러미가 있으며, 연조이다. Genus Syngnathoides는 "잘피실고기속", S. biaculeatus는 "잘피실고기"로 각각 국명을 신칭한다.