• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.53 no.4
• /
• pp.637-649
• /
• 2020

An ideal 3D primitive equation model is implemented to investigate upper ocean response to typhoons, focusing on rightward bias (RWB) which means an appearance of an intensified sea surface cooling to the right side of the typhoon track. The model has 26-stratified levels and a flat bottom (1000 m), covering a rectangular domain of about 3,060 km×3,300 km with four open boundaries. The sea water is forced by an atmospheric pressure and a gradient wind of the typhoon. The model well reproduces the RWB in previous observations and theoretical analyses. For the fast moving typhoon (FMT) (-8m/sec), the model shows that in the mixed layer (ML), the RWB in the SST noticeably appears clearly illustrating the coupling between inertial motion and wind stress, but in the subsurface layer (-100m), the RWB does not emerge since a cyclonic current field (CCF) caused by wind stress curl is primarily dominant. For the slowly moving typhoon (SMT) (-3m/sec), however, the RWB does not emerge because the coupling is weakened and the CCF is rather predominant even in the ML. In the model, we conclude that the RWB noticeably emerges in the FMT but does not emerge in the SMT related to predominance of CCF.

• The Mathematical Education
• /
• v.56 no.4
• /
• pp.387-405
• /
• 2017

The purpose of this study is to investigate the change of students 'perception and expression about the motion of object following distance function $={x \atop 3}$ and distance function $y=\frac{x^3}{3}+3$ according to the necessity of research on students' perception and expression about integral constant. In this paper, we present the recognition and the expression of the difference of the constant in the relationship between the distance function and the speed function of the students, while examining the process of constructing the speed function and the inverse process of the distance function. This provides implications for the relationship between the derivative and the indefinite integral corresponding to the inverse process. In particular, in a teaching experiment, a constructive activity was performed to analyze the motion of two distance functions, where the student had a difference of the constant term. At this time, the students used the expression 'starting point' for the constants in the distance function, and the motion was interpreted by using the meaning. This can be seen as a unique 'students' mathematics' in the process of analyzing the motion of objects. These scenes, in introducing the notion of the relation between differential and indefinite integral, it is beyond the comprehension of the integral constant as a computational procedure, so that the learner can understand the meaning of the integral constant in relation to the motion of the object. It is expected that it will be a meaningful basic research on the relationship between differential and integral.

• Journal of the Korea Computer Graphics Society
• /
• v.2 no.1
• /
• pp.7-14
• /
• 1996

A particle system is defined as a collection of primitive particles that together represent irregular and ever-changing objects such as smoke, clouds, waterfalls, and explosions. A particle system can be a powerful tool for modeling a deformable object's motion and change of form since it has dynamic properties with time. As an object becomes more complicated and shows more chaotic behavior, however, we need much more parameters for describing its characteristics completely. Consequently, the conventional particle system leads to difficulty in managing all of the parameters properly since one parameter can affect the others. Moreover, motion equations for representing particles' behavior are usually approximated to gain speed-ups. The inevitable errors in calculating the equations can cause an unexpected outcome. In this paper, we present a new approach of applying fuzzy contol to mage particles' motion and attributes changes over time. We also give an implementation result of a fuzzy particle system to show the feasibility of the proposed method. Applications of the system to explosions, nebulae, volcanos, and grass are presented.

• Journal of KIISE:Computer Systems and Theory
• /
• v.33 no.8
• /
• pp.455-476
• /
• 2006

An avatar script language consists of commands set which is used to control avatar behaviors in cyberspace. The script language should be abstract from complex low-level concepts, so that a user can write down a scenario script easily without concerning about physical motion parameters. Also, the script should be defined in a standard format and structure to allow reusing in various implementation tools. In this paper, a layered script language is proposed for avatar behavior representation and control, which consists of task-level behavior, high-level motion and primitive motion script language. The script language of each layer represents behavior elements for a scenario scripting interface, an avatar motion sequence, and geometric information of implementation environment, respectively. Therefore, a user can create a scenario script by abstract behavior interface and a script can be applied to various implementations by the proposed translating process. A presentation domain is chosen for applying the proposed script language and the implementation result shows that the script is flexibly applied in several applications.

• Journal of Institute of Control, Robotics and Systems
• /
• v.6 no.5
• /
• pp.404-414
• /
• 2000

This paper addresses the development of a 3-fingered humanoid robot hand system and a real-time grasp synthesis of multifingered robot hands to find grasp configurations which satisfy the force closure condition of arbitrary shaped objects. We propose a fast and efficient grasp synthesis algorithm for planar polygonal objects, which yields the contact locations on a given polygonal object to obtain a force closure grasp by the multifingered robot hand. For an optimum grasp and real-time computation, we develop the preference and the hibernation process and assign physical constraints of the humanoid hand to the motion of each finger. The preferences consist of each sublayer reflecting the primitive preference similar to the conditional behaviors of humans for given objectives and their arrangements are adjusted by the heuristics inspired from human's grasping behaviors. The proposed method reduces the computational time significantly at the sacrifice of global optimality, and enables the grasp posture to be changable within two-finger and three-finger grasps. The performance of the presented algorithm is evaluated via simulation studies to obtain the force-closure grasps of polygonal objects with fingertip grasps. The architecture suggested is verified through experimental implementation to our robot hand system by solving the 2- or 3-finger grasp synthesis.

• Journal of Korean Physical Therapy Science
• /
• v.3 no.4
• /
• pp.189-196
• /
• 1996

The purpose of this review are that what is the concept of sport P. N. F and to give the information about proprioceptive neuromuscular facilitation technique when the sport physical therapy will be needed in field. Technique of proprioceptive neuromuscular facilitation are methods of placing specific demands in order to secure a desired response. Greatest emphasis was placed on the application of optimal resistance throughout the range of motion, using many combinations of motions which were related to primitive patterns and employment of postural and righting reflexes. The treatment after sport injury patient is required that two component actions of muscles as well as permitting action to occur at two or more joint. The effect of P. N. F and of sprot P. N. F are reviewed. Implications for treatment of sport disability are suggested.

• 제어로봇시스템학회:학술대회논문집
• /
• 1997.10a
• /
• pp.1621-1623
• /
• 1997

Use of teaching pendant is the most widespread and economical way to teach desired motion to robots. It is also very primitive,time consuming and ineffective way of teaching which has not changed since the early days of robot. In order to reduce the teaching effor, a new efficient form of teaching is needed. Also, the recent robotics research trend into service robots such as home robot, nurse robot and medical robot calls for a new teaching method which is both easy and inexpensive. In this paper, the design and operation principle of a low cost force/moment sensor is presented. The proposed sensor architecture is so simple and inexpensive that it opens the prospect for a new paradigm of robot teaching which is easy and efficinet. Other prospective areas of application are tele-manipulation of robots wher it can be used in master arm, and virtual environment where it can be used as an user input device.

• International Journal of Aeronautical and Space Sciences
• /
• v.10 no.2
• /
• pp.148-160
• /
• 2009

By the development of recent technology, a new variant of rotorcrafts having four rotors start drawing attention from aerial-robotics engineers more than before. Its potential spans from just being control device test bed to performing difficult task such as carrying surveillance device to unreachable places. In this regards, modeling a quad-rotor is significant in analyzing its dynamic behavior and in synthesizing control system for such a vehicle. This paper summarizes the modeling of a mini quad-rotor aerial vehicle. A first principle approach is considered for deriving the model based on Euler-Newton equations of motion. The result of the modeling is a simulation platform that is expected to acceptably predict the dynamic behavior of the quad-rotor in various flight conditions. Linear models associated with different flight condition can be extracted for the purpose of control synthesis.

• Proceedings of the Korea Multimedia Society Conference
• /
• 2000.11a
• /
• pp.475-478
• /
• 2000

사람의 몸 동작을 인식해야하는 여러 응용분야에서의 필요성이 대두되면서 이 분야로의 연구가 활발해지고 있다. 이 논문은 사람의 비언어적 행동을 자동적으로 분석할 수 있는 인식기 개발에 관한 것으로 실세계 3 차원 좌표값을 입력으로 하는 사람 몸 동작 패턴 분류기의 구현방법을 소개한 것이다. 하나의 사람 몸 동작은 각 몸 구성 성분(손, 아래팔, 위팔, 어깨, 머리, 몸통 등)의 움직임을 조합해서 정의한 수가 있기 때문에 개별적인 각 몸 구성성분의 움직임을 인식하여 조합해서 임의의 동작을 판별하려는 방법을 적용한다. 사람 몸 동작 패턴 분류기는 측정된 실세계 3 차원 좌표 자료를 양자화한 후 xy, zy 평면에 투영한 값을 자자 구한다. 이 결과를 각각 8 방향 체인 코드로 바꾸고 2 단계 체인 코드 평활화 사업을 하여, 4 방향 코드 체적화 및 대표 코드로의 압축단계를 거친다. 이로서 생성된 프리미티브 패턴나열들을 동작 클래스별로 분류하여 프리미티브 패턴나열의 확장으로 각각의 식별기를 구축하여 각 몸 구성 성분별 동작들을 분류한다. 일련의 실험이 행해져 그 타당성을 확인하였으며, 차후에 이 분류기는 비언어적 행동 분석을 위한 사람 몸 동작 인식기의 전처리 단계로 사용되어진 것이다.

• Korean Journal of Computational Design and Engineering
• /
• v.4 no.4
• /
• pp.295-311
• /
• 1999

An increasing attention is paid to STEP-NC, the next generation CNC controller interfacing STEP-compatible data. In this paper, we first propose an Architecture for the STEP-NC (called FBCC: Feature Baled CNC Controller) accepting feature code compatible with STEP-data, and executing NC motion feature by feature while monitoring the execution status. The main thrust of the paper has been to develop an automatic on-line tool path generation and modification scheme for milling operation. The tool path it generated iota each feature by decomposing into a finite number of primitive features. The key function in the new scheme is haw to accommodate unexpected execution results. In our scheme, the too1 path plinker is designed to have a tracing capability iota the tool path execution so that a new path can be generated from the point where the operation is stopped. An illustrative example is included to show the capability of the developed algorithm.