• Journal of the Korean Chemical Society
• /
• v.43 no.4
• /
• pp.469-474
• /
• 1999

In this study, the simulation program using the randomwalk model is developed. Generally, students in the chemistry class have some difficulties to understand the motion of atomic particles or molecules. And then, they have many mis-conceptions about the motion of molecules. This program expressed by the computer simulations using the randomwalk theory may help students to understand visually the process of molecular motion. This program can be used easily, because it is based on Web by application of JAVA languages. The program consists of two parts. One is 'Diffusion' program, expressing the process of molecular diffusion as a computer simulation. Another is 'Randomwalk' program, expressing the trajectory of molecular motion to help the students to follow the random motion virtually.

• The korean journal of orthodontics
• /
• v.27 no.2
• /
• pp.273-282
• /
• 1997

The purpose of this study was to evaluate changes in mandibular movement patterns after orthognathic surgery in skeletal Class III patients. The sample consisted of 20 Class III malocclusion patients(9 males, 11 females). Just before and after(2-7months) surgery, maximum opening & closing movement, mandibular border movement on sagittal, frontal and horizontal planes were recorded using Sirognathograph & BioPak EGN. On each record, 21 items were measured and statistically analyzed. The results were as follows 1. Angle of protrusive movement on sagittal plane showed greatest change after surgery. Also, as the incisal guidance was established by surgery, straight path of protrusive movement became curved line. 2. Maximum opening distance and maximum antero-posterior distance on maximum opening & closing movement, maximum opening distance on sagittal plane, angle of left lateral excursion on frontal plane were statistically significant after snrgery(p<0.01). 3. Maximum width of lateral excursion on frontal plane, distane of right lateral excursion and angle of maximum left lateral excursion on horizontal plane were statistiraily significant after surgery(p<0.05). 4. Maximum opening distance and maximum antero-posterior distance on maximum opening & closing movement showed significant differences according to post-surgical time(p<0.05). More recovery of range of movement occured in 5-7month group than in 2-3month group. 5. As the occlusal interferences were removed by orthognathic surgery, irregular opening & closing path became smooth curve.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1998.04a
• /
• pp.194-199
• /
• 1998

축어긋남이 있는 회전체-볼베어링계에 대한 동적모델을 이용하여, 각축어긋남에 의한 2x 축진동현상을 조사하였다. 이때 유효베어링강성계수를 정의하여 축어긋남과 불균형량에 의해 발생되는 강성계수의 평균과 동기 변화성분을 운동방정식에 도입하였다. 수치해석과 실험결과는 각축어긋남에 의한 바나나 형태의 선회궤적이 회전체계 임계속도의 1/2이 도는 속도영역에서 뚜렷이 나타나는 것을 보여주었다.

• Journal of Biosystems Engineering
• /
• v.18 no.2
• /
• pp.91-99
• /
• 1993

Kinematic analysis was made on a gear type high speed planting mechanism for riding-type rice transplanters. The kinematic equations thus derived were computer coded to simulate its motion characteristics such as a planting locus, velocities and accelerations of gears and planting knife, etc. Using the simulation program a sensitivity analysis of design parameters was also carried out to determine their effects on the planting performance. Of the design parameters the eccentricity of the gear was found most influential.

• Journal of Biomedical Engineering Research
• /
• v.14 no.1
• /
• pp.1-8
• /
• 1993

In this study, the extractions of formants and articulatory motion trajectories for Korean complex vowels are performed by using the RLSL adaptive linear prediction filter. This enables us to extract accurate spectrum in transition of speech signal. This study shows that the RLSL algorithm is superior to the Levinson algorithm, specially in transition part of speech.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.24 no.5
• /
• pp.753-761
• /
• 1987

Approximation of a Cartesian straight line motion with linear interpolation in the joint space has many desirable advantages and applications. But inappropriate determination of the corresponding subtravelling and transition times makes such joint-trajectories violate the input torque/force constraints. An approach that can overcome this difficult and yield the joint trajectories utilizing the allowable maximum input torque/force is established in this paper. The effectiveness of these results is demonstrated by using a three-joint revolute manipulator.

• Proceeding of EDISON Challenge
• /
• 2016.03a
• /
• pp.489-492
• /
• 2016

In this paper, 본 논문에서는 경사/장애물/특수표면을 이동할 수 있는 얀센 매커니즘 기반의 보행기구 설계에 대해 다루고 있다. 얀센 매커니즘 자체의 조건과 전체 보행기구의 조건을 알아보며, 기구의 완전한 회전운동 조건과 장애물이 있는 거친 표면을 이동할 수 있는 조건을 알아보고자 한다.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 1994.06b
• /
• pp.66-71
• /
• 1994

The motion of dynamically loaded journal in the connecting rod big-end bearings is considered and then equations of motion are derived. Dynamical characteristics of big-end bearings are derived by perturbation method and linearized spring and damping coefficients are calculated. Numerical intergrations of equations of motion ure performed by $\rho$-family method. This paper gives various journal orbits in a big-end bearing depending on external force cycle and bearing parameters

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2000.11a
• /
• pp.23-23
• /
• 2000

대표적인 잠수함 발사 유도탄의 수중에서의 발사 개념에 대한 기술 동향을 분석하였다. 세계 각 국의 수중 발사 유도탄 중 발사 형태가 특히 다른 Tomahawk, Sub Hapoon, Exocet SM39 유도탄에 대하여 그 발사 방법에 따른 기술 동향과 장단점을 비교 분석하였다. 대표적인 서방 세계 수중 발사 유도탄인 Tomahawk는 여러 가지 다른 형태가 있지만 잠수함 발사는 Wet Capsule에 의해 보호되며 어뢰 발사관을 이용하여 압축수에 의해 수중으로 배출되는데 잠수함과의 안전거리에서 견일줄이 유도탄 진행에 따라 장력을 발생 부스터를 점화시킨다. 이 부스터에 의해 수면까지 부상하며 부스터에 설치되어 있는 수중궤적 제어용 Jet-Tab이 수중운동을 제어한다. 수면에서 부스터의 추진력에 의해 대기로 진입하는데 일정속도 이상으로 가속된 후 부스터를 분리시키며 Turbo 엔진이 점화되어 계속 비행하게 된다.(중략)

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.11
• /
• pp.1391-1398
• /
• 2011

Biomechanical analysis of arm motion during steering was performed using a motion analysis technique. Three-dimensional position data for each part of arm are fed into an interactive model combining a musculoskeletal arm model and the mechanical steering system to calculate joint angles and torques using inverse kinematic and dynamic analyses, respectively. The analysis shows that elbow pronation/supination, wrist flexion/extension, shoulder adduction/abduction, and shoulder flexion/extension have significant magnitudes. Sensitivity analysis of the arm joint motion with respect to seating posture and steering wheel configuration is carried out to investigate the qualitative influence of the seating posture and driver's seat configuration on the steering behavior.