• 대한기계학회논문집A
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• 제29권2호
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• pp.176-187
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• 2005

This paper presents an evaluation of joint configurations of a robotic finger based on kinematic analysis. The evaluation is based on an assumption that the current control methods for the fingers require that the contact state specified by the motion planner be maintained during manipulation. Various finger-joint configurations have been evaluated for different contact motions. In the kinematic analysis, the surface of the manipulated object was represented by B-spline surface and the surface of the finger was represented by cylinders and a half ellipsoid. Three types of contact motion, namely, 1) pure rolling, 2) twist-roiling, and 3) slide-twist-rolling are assumed in this analysis. The finger-joint configuration best suited for manipulative motion is determined by the dimension of manipulation workspace. The evaluation has shown that the human-like fingers are suitable for maintaining twist-rolling and slide-twist-rolling but not for pure rolling. A finger with roll joint at its fingertip link, which is different from human fingers, proved to be better for pure rolling motion because it can accommodate sideway motions of the object. Several kinds of useful finger-joint configurations suited for manipulating objects by fingertip surface are proposed.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1615-1620
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• 2003

Kinematic calibration is a process whereby the actual values of geometric parameters are estimated so as to minimize the error in absolute positioning. Measuring all components of Cartesian posture, particularly the orientation, can be difficult. With partial pose measurements, all parameters may not be identifiable. This paper proposes a new device that can identify all kinematic parameters with partial pose measurements. Study is performed for a six degree-of-freedom fully parallel Hexa Slide manipulator. The device, however, is general and can be used for other parallel manipulators. The proposed device consists of a link with U joints on both sides and is equipped with a rotary sensor and a biaxial inclinometer. When attached between the base and the mobile platform, the device restricts the end-effector's motion to five degree-of-freedom and can measure position of the end-effector and one of its rotations. Numerical analyses of the identification Jacobian reveal that all parameters are identifiable. Computer simulations show that the identification is robust for the errors in the initial guess and the measurement noise. Intrinsic inaccuracies of the device can significantly deteriorate the calibration results. A measurement procedure is proposed and formulations of cost functions are discussed to prevent propagation of the inaccuracies to the calibration results.

• 한국초전도ㆍ저온공학회논문지
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• 제5권1호
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• pp.40-43
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• 2003

The phase transformation, variation of secondary phase, and critical current density $(J_c) for (Bi,Pb)_2Sr_2Ca_2Cu_3O_10 (2223)$ tapes have been studied through the thermal slide heat treatment (TSHT) process. This process consists of a multiple variations of oxygen partial pressures and temperatures at the initial heat treatment During the initial heat treatment some secondary phase such as $(Ca,Sr)_2CuO_3(2/1 AEC), (Ca,Sr)_{14}Cu_{24}O_{41} (14/24 AEC), and (Bi,Pb)_2Sr_2CuO_y$(2201, amorphous phase) farm in Bi-2223 tapes, especially at the 2223 grain boundaries. These secondary phases are detrimental to the phase transformation and final properties. In order to control the secondary phase in Bi-2223 tapes the amount and size of secondary phases among the TSHT process were observed. The results indicate that the amount and particle size of AEC particles were smaller when the TSHT process was used than when the normal process at the initial heat treatment was used which results in the improved $J_c$ properties after the final process.

• 정보보호학회논문지
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• 제28권5호
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• pp.1113-1118
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• 2018

스마트 기기에서 지문 인증은 가장 널리 쓰이는 생체 인증 방식이지만 스마트 기기의 특성에 의해 위조 지문에 취약하다. 본 논문에서는 먼저 기기 사용 후 남은 지문 흔적인 스머지를 활용하여 정당한 사용자의 협조 없이 위조 지문을 만들고 실제 상용 스마트폰의 지문 인증 통과가 가능함을 검증하였다. 이러한 스머지 기반 공격을 방지하기 위한 기술적 대응 방법으로 터치 스크린 위에서 지문 인증을 수행하고 UI를 옆으로 끌어서 지문 흔적을 제거하는 방법인 under-screen Touch ID with slide bar가 제안된 바 있다. 본 논문에서는 앞서 제안한 공격 방법과 이에 대한 대응 방법에 관한 사용자 인식을 61명 규모 사용자 설문 연구를 통해 분석하였다.

• 한국안광학회지
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• 제3권1호
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• pp.237-242
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• 1998

$80SiO_2-20TiO_2$(mol%)의 무색투명한 비정질 박막을 현미경용 슬라이드 유리판과 사파이어 위에 tetraethyl orthosilicate와 titanium trichloride의 전구체 용액을 사용하여 스핀코팅방법으로 제조하였다. 코팅 후 $750^{\circ}C$에서 열처리된 박막은 높은 투과율과 낮은 반사율을 보였다. 슬라이드 유리판에 코팅한 $SiO_2-TiO_2$ 박막의 경우에 나트륨이온과 산소 간의 강한 상호작용에 의하여 고온과 높은 습도에서도 안정성이 우수하였다.

• Journal of Biosystems Engineering
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• 제28권5호
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• pp.429-438
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• 2003

This study exploits the robot system which is necessary in gene study and bio-technology industry. As well, a DNA chip, which of use has been increased recently, can be manufactured with this system. The robot consists of a device spotting DNA on the silylated slide, a well plate, a bed for fixing well plates, devices of washing and drying the pin in DNA spotting .device, a distillation-water vessel, and a discharge vessel of wash water. We made the period of sticking DNA to the pin on the well plate to be 15 seconds. The spot size of DNA was set to be 0.28 mm on the average by bringing the slide into contact with pin during 1 second. If DNA is spotted in minimum space possible about 0.32mm, this system can stick about 8,100 DNA spots on the well plate with this rate. Analyzing the procedure: Movement starts, Pin washes, dries, and smears DNA on the well plate. Spotting DNA onto 12 chips took 2 minutes and 50 seconds.

• Wind and Structures
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• 제30권1호
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• pp.15-27
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• 2020

This paper reports the study on development and verification of numerical models and analyzes of flow at high speed around structural elements in the shape of a curved pipe (e.g., a fragment of a water slide). Possibility of engineering estimation of wind forces acting on an object in the shape of a helix is presented, using relationships concerning toroidal and cylindrical elements. Determination of useful engineering parameters (such as aerodynamic forces, pressure distribution, and air velocity field) is presented, impossible to obtain from the existing standard EN 1991-1-4 (the so-called wind standard). For this purpose, flow at high speed around a torus and helix, arranged both near planar surface and high above it, was analyzed. Analyzes begin with the flow around a cylinder. This is the simplest object with a circular cross-section and at the same time the most studied in the literature. Based on this model, more complex models are analyzed: first in the shape of half of a torus, next in the shape of a helix.

• 한국조경학회지
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• 제22권3호
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• pp.29-40
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• 1994

The purpose of this study was to investigate factors and variables which have significant effects on satisfaction of urban pedestrian sidewalk in taejon city, and to suggest basic information for urban pedestrian sidewalk. These works consist of two phase; The first, tested the user's degree of satisfaction for 37 spots of pedestrian sidewalk slide and then selected 10 spots slide by the stratified random sampling method. The second, analyzed factors and variables of satisfaction of urban pedestrian sidewalk using the semantic differential scale method, and then processed by mean score, correlation, factor analysis, multiful algorithm. The results were summarized as follows; 1) The relationship between the man group and the woman group was highly correlated as well as between the student group.1 and the student group.2 hense these groups statistically showed no difference in satisfaction ratings. 2) Pedestrian sidewalk width, cleanness, pavement materials and construction condition can be significant variables of satisfaction of urban pedestrian sidewalk. 3) Factors covering the satisfaction of urban pedestrian sidewalk have been found to be Environment of pedestrian sidewalk, Vegetation of pedestrian sidewalk and Form of pedestrian sidewalk. By using the control method for the number of factors, C.P. has been obtained as 62.8%.

• 한국철도학회논문집
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• 제9권2호
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• pp.230-236
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• 2006

For a short-term measurement to reduce an accident on a railroad crossing, it is necessary to find out the weakness and problems of existing equipment in the railroad transportation system. The analysis of railroad crossing accidents shows that main causes of accidents (24.9%) are the careless driving including an engine problem, damage on the safety equipment, slide on the snow, and an engine stop on the railroad crossing. Therefore, it is required to install a sensor, or to make a crossing gate at the exist for detecting obstacles on a railroad to prevent collisions among trains. This paper suggests 'a panel sensor using the strain gauge' to make up the weaknesses of the sensing Dead Zone, which are caused by using a laser method, and to detect any small objects passing railroads in order to reduce the errors, which are occurred in the earth magnetic field for controlling Exit Slide Crossing Arm Detector. The device, suggested in this paper, is verified with detecting any small objects passing the railroad, with judging entry decision clearly, and with controlling passing gate and obstruction warnings/cautions obstacles at the same time, through an experimental test.

• 한국동물위생학회지
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• 제29권2호
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• pp.103-110
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• 2006

Ticks cause economic losses to the deer industry by decreasing the growth and production of the farmed animals. The mediation of ticks affects humans and animals by causing contagious disease both directly and indirectly. Blood from farmed deer from the areas near Jangsu branch was collected for screening of infectious protozoa and rickettsial disease. Seventy deer blood samples were collected from 30 different deer farms located in Jinan, Jangsu and Muju. This blood samples were used for blood slide smear examination and hematological analysis. DNA from these samples was extracted and was used for PCR analysis for detection of gene fragments of Theileria spp, Babesia spp, Anaplasma spp and Ehrlichia spp. In the blood slide smear examination and PCR analysis all samples did not show presence of protozoal and rickettsial diseases. Eight blood samples showed anemia, 1 sample showed iron deficiency and 7 samples showed regenerative anemia. Results for PCR analysis showed 2 samples were positive for T orientalis. All DNA samples were negative for Babesia spp, Anaplasma spp, and Ehrlichia spp.