본 연구는 시각 피드백이 조준 운동의 제어에 미치는 영향을 알아보기 위하여 시각 피드백 처리시간을 과대 평가할 가능성이 있는 요인들을 통제한 상황에서 시각 피드백과 시각 피드백 관련 변인들을 체계적으로 다양하게 통제하여 유사한 네 개의 실험을 수행하였다. 실험1은 다양한 속도로 수행되는 운동하에서 시각 피드백을 다양한 시점에서 철회하여 시각 피드백이 동작실행의 정확성에 미치는 영향을 관찰함으로써 시각 피드백 처리시간을 알아 보려는 의도로 수행하였다. 이와 동시에 시각정보가 일정시간(최소한 250㎳)동안 감각기억(sensory memeoy)의 형태로 표상화되어 기억됨으로써 감각기억에 기초를 둔 동작 제어의 가능성을 검증하기 위함이었다. 실험은 3×5의 2요인 피험자내 설계를 이용하여 시각 피드백과 동작시간 요인을 통제한 가운데 단일 표적조준과제를 이용하여수행하였다. 실험2는 빠른 속도(160㎳)로 수행되는 운동하에서 시각의 철회를, 동작개시를 시점으로 다양하게 지연시켜 시각조건과 비교함으로서 동작 수행 중 시각정보가 어떠한 시점에 영향을 미치는지를 알아보려는 목적으로 수행하였다. 실험은 단일요인 피험자내 설계를 이용하였으며, 실험조건은 시각 피드백을 통제하는 다섯 가지 조건으로 구성하였다. 실험3은 예비신호와 동시에 철회하였던 시각 피드백을 반응신호, 동작개시와 동시에 그리고 동작개시 60㎳후에 부여하여 시각이 조준 동작을 사전에 정하는 데 사용되는 것을 방지한 상황에서 동작실행의 정확성을 관찰함으로써 시각 피드백이 동작실행의 정확성에 미치는 영향을 관찰하고자 하였다. 실험은 단일 요인 피험자내 설계를 이용하였으며, 실험조건은 시각 피드백을 통제하는 네 가지 조건으로 구성하였다. 실험4는 동작거리와 동작시간 그리고 시각 피드백을 통제하는 가운데 동작실행의 정확성을 관찰하여 시각 피드백이 조준운동의 제어에 미치는 영향을 규명하고자 하였다. 실험은 2×2×3의 3요인 피험자내 설계가 이용하여 동작거리와 동작시간 그리고 시각 피드백이 통제되는 가운데 실험을 수행하였다. 수집한 자료를 일차적으로 반응시간과 동작시간에 의하여 자료로서의 채택 여부를 검토한 뒤에 동작실행의 정확성(동작오차)을 분석한 결과, 다음과 같은 결론을 얻었다. 첫째, 시각 피드백은 200㎳ 이내에 빠른 시간에 처리될 수 있다. 둘째, 거리오차의 경우 시각 피드백은 동작의 후기 단계에서 중요하며, 방향오차의 경우에는 시각 피드백이 동작의 초기 단계에서 중요하다. 셋째, 시각조건과 비시각조건 간에서 동작오차의 차이는 150-300㎳의 동작시간에서는 일정하였으나 450㎳의 동작시간에서는 증가하였다. 그리고 이러한 경향은 동작거리가 길수록 강하게 나타났다.

This project was conducted in order to examine visual of the elite athletes and compared the different visual abilities between elite and non-elite athletes by employing seven different visual ability tests. After administring the visual ability tests, important visual characteristics which might have important role to become elite athetes were identified. In the second experiment, two different visual abilities(dynamic visual acuity and depth perception) selected in order to examine the visual training effect for baseball hitting performance for these visual abilities had shown the most relevant visual characteristics for batting performance in the first experiment. The results revealed there were different visual characteristics between athletes in different sports (archery, shooting, ice hockey, baseball), and elite and non-elite athletes. The results also found specific relationship between certain visual characteristics and the sports events. The results of the second experiment revealed the subjects in the experiment group(visual training group) improved their visual abilities significantly through specially designed visual training in the laboratory and the improved visual abilities had positive effect on batting performance in the field.

Based on Bernstein` s (1967) theoretical tenets that skill consists in organizing movement elements (e. g. , body links) into a controllable unit with manageable degree of freedom through the application of appropriate equations of constraints, motor skill learning is theorized as the acquisition of efficient constraining of body segments involved in desired goal movements. To elucidate the spatial and temporal patterns of constraints, a golf swing movement by the skilled golfers and the novice players, respectively was filmed using high speed camera with 300fpt. Analyses were made of the spatial and temporal structures of changes in joint angles around shoulders, elbows, and wrists. Results indicated that marked differences existed between the skilled and the novice players in both spatial patterns and temporal relationships of angular changes. Specifically, the unskilled novice players were more frequent in angular changes in all related joints and were also bigger in amplitude of angular changes. Also noted in the unskilled was that the times of angular changes of body segments were generally late in the whole movement phase. These findings were interpreted to mean to support Bernsteinian tenets and to suggest that practice induces changes in constraints both spatially and temporally, so that skilled movements can be possible by efficiently redefining relationships among several body segments.

This paper aims at creating the measurement of athletes` stress. About 340 athletes attending high schools or universities were selected as the subjects for the purpose of this study, but 316 of them were the real subjects for the ultimately operated data on the factors causing stress. Questionaires adapted from Competitive State Anxiety Inventory(CSAI) designed by Martens, Burton, Rivkin and Siman were used to put Competitive Anxiety Factor to the test ; questionaires included in Sports Cohesion Instrument (SCI) developed by Yukelson, Weinberg and Jackson were used to test Team Cohesion Factor ; questionaires presented in A Study on the Measurement of Job Stress (I) by Lee Jong-mok and Park.Han-ki were modified to be suitable for athletes and used to test communication factor and family factor. 54 questions were selected out of preliminary questionaires for testing the above -mentioned factors, and principal component factor was analyzed by means of Pearson correlation coefficient matrix on the basis of the responses to 54 questions. As a result, 12 factors and variable quantities that they could take turned out to be 60.20% . 47 questions, which had more than .30 as each factor loading in 12 factors, were selected out of 54. questions as a resultof Uarimax Rotated Factor Analysis of these 12 factors. The selected 12 factors game, counsel, sports-external disturbance, team cohesion, athletic sports, communication, training, spectators. We suggest that athletes undergo stress while they are under situations-competitive or ordinary-concerned with these 12 factors.

We could say that the knowledge of results is very important factors in the motor skill learning. This paper was analyzed to stipulate how inside-kick of soccer affect to perform when we present the accuracy of the knowledge of results and post-knowledge of results interval. I randomly selected 60 students in the Hakjin elementary school in Busan, and divided 6 groups. The results were as follows. 1. The qualitative and quantitative knowledge of results in the early motor learning stages were not significant difference in each other of the exercise and the transfer performance. 2. When we tried various time interval of the post-knowledge of results interval in the early motor learning stages, there was very significant difference at P=0.05 level in transfer performance . 3. There was no significant between the accuracy of the knowledge of results and post-knowleclge of results in interaction effects. 4. The most effectively performed group in this experiment was as the quantitative knowledge of results who performed 6 seconds of post-knowledge of results interval.

The purpose of this research is to find the effect of motor learning if quantitative knowledge of results and qualitative knowledge of results are presented according to task natures. As the experimental method, I execute a kind of linear positioning task adopting 36 college students as objects of this study. After measuring movement time and distant error using a touch pad adhered a circuit and a programmed personal computer system, I calculate the mean of distant error and standard deviation. I come to get these results as followings to perform factorial ANOVA with repeated measures providing a basis for this computation. The task natures and forms of knowledge of results have not influences on the effect of motor learning. The performance effect according to task natures makes a meaningful difference, that is students show high accuracy of motion when they have enough time to perform the task voluntarily than under the condition that they have to do the task as soon as possible.

This study investigated the effects of different sequence structures on the bilateral transfer of learning from one sequence to another. Subjects were asked to respond to visual stimulus of "x" mark appeared in a particular sequence on the CRT at one of four locations arranged horizontally. They were instructed to respond to the visual signal by pressing the corresponding keys with their four fingers. After practicing one serial pattern for a substantial period of time with one hand, the subjects were randomly assigned to one of two experimental conditions and a control condition [ hierarchy (n=6) , vs , linear (n=6) , control (n=6) ] . Reaction time and latency profile constituted the dependent variables and learning of the sequence was evaluated by measuring the amount of facilitation of the performance on the transfer tasks. The findings support the notion that the internal representation of a sequence organiges in hierarchically, rather than linearly and the executionin of movement sequence is controlled hieararchically even though different effector(different hand in this study) . In addition, the results provided strong evidence for the notion that the subunits of movement can be interchangeable once subjects establish interval structure of the sequence.

The purpose of this study was to find the effect of the two different types of movement velocity control on timing variability and temporal structure parameters (time to peak positive acceleration, duration of positive acceleration, peak positive acceleration) of acceleration-time function. Subjects were 6 male students, and task was arm flexion movement. The results showed that when movement distance increased with movement time fixed, timing variability was constant, also time to peak positive acceleration and duration of positive acceleration were constant, but peak positive acceleration increased with statistical significance. And when movement time increased with movement distance fixed, timing variability increased, and time to peak positive acceleration, duration of positive acceleration increased, but peak positive acceleration decreased. The results suggest that each control types of movement velocity are different fundamentally, and movement velocity as a function of movement distance is achieved by the increase of peak positive acceleration with time to positive acceleration and duration of positive acceleration constant. Namely, this type of velocity is modulated by the change of force with phasing of generalized motor program, and movement velocity as a function of movement time is achieved by the extension of time to peak positive acceleration and duration of positive acceleration, Thus, this type of movement velocity is modulated by the change of phasing and relative force generalized motor program.

There have been increasing efforts to find the source of motor response error variability and to apply this information for the efficiency of human activity in real life. The purpose of this study was to examine of movement amplitude and movement time, and movement velocity on the space-timing variability. Subjects(6 male student) engaged in an angular timing task at four different movement times(150, 200, 250 and 300 msec) over four movement ranges, respectively, Movement velocity were 50, 120, 180, 240, 300, 400 deg/sec. The result indicated that first, spatial variability increased and timing variability decreased as amplitude increased in all movement times, but spatial variability decreased and timing variability increased as movement time increased in all movement amplitude. Spatial variability was changed linearly with increment of movement amplitudes and movement times, and timing variability was changed linearly with increment of movement amplitude. But timing variability was changed curvilinearly with increment of movement time. Second, spatial variability increased and timing variability decreased as movemnt velocity increased, and response variability changed curvilinearly with increment of velocity. These results suggest that movement amplitude, movement time and movement velocity are parameters of response variability.

The characteristcs of children`s motor performance are slow response, low accuracy, greater var iability, inappropriate response, and ignoring KR when they perform at will. Not only physical growth, development, and maturation but also information processing capacity results in children`s motor performance deficits. In the late 1970s, motor development theorists accepted information processing model to explain the motor performance differences between adults and children. they try to clarify that whether the performance differences are due to structure(capacity) or function (control process) . To date, many researches show that the performance differnces result from children`s lack of control process rather than children`s small capacity. Children do not know how to lable the incoming information, how to rehearse to memorize the information in the long-term store, and how to organize the information already existed in their memory effectively, However, if children have enough information about specific task, they spontaneously develop adult-like memory strategy. This facts are due to their great knowledge base. Therefore, even though their sophisticated memory strategy can not compensate all their motor deficits, the role of teachers and coaches is to give children various movement experiences making their knowledge base bigger.

Most movements executed in sport performance and everyday life are aimed at visual objects and are controlled visually. The role of visual feedback in control of movements has been a central issue in the study of motor behavior since Woodworth`s research in 1899. The time required to identify, decide, and initiate within-movement corrections based upon visual feedback has been called visual feedback processing time. The estimated visual processing time in most early experiments is about 250-300msec. However, there have been several evidences suggesting that visual feedback could be processed and used in lesser time. The evidences for faster visual processing time comes from the selective exclusion of visual feedback, the control of saccadic eye movement, and the analysis of movement trajectory. These experiments estimated that the visual processing time is about 120msec or less.

When a ship is sailing on the sea, she has the six-degrees of freedom of motion. It means that she meets a lot of dangerous situations. Especially, when the VLCC is travelling in irregular sea, the slamming, the deck-wetness and the propeller racing are occured with the sea state she is on. These are the representative steps that a heave-to and a scudding are used for a ship building , but for a predominance in both. The author intends to clarify this problem theoretically. The methods of statistical calculation are based with the ITTC spectral formulation and with the assumption that the wave height histogram follows the Rayleigh distribution. In this study, the author gives an attention on the relative bow motion to a wave in the irregular sea. It is verified that the relative diplacement at the bow to sea level in the following sea is less than that in the head sea. It is confirmed that, therefore, one have to sail with scudding when he is threatened to heave-to at a rough sea. But he must bear the propeller racing in mind in the cases.

In this paper the dynamic effects due to the free water motions in tanks upon the lateral motion of a floating body in regular waves are calculated, in order to obtain the relationship between a motion of a floating body and that of the free water in tanks. Under the assumption that the fluid is ideal and motion amplitudes are small, velocity potential of the fluid in tanks is calculated by the source distribution method and the hydrodynamic forces and moments are calculated by the integration of fluid pressures over the tank surface. Hydrodynamic effects of the fluid on the floating body are expressed in terms of added mass and coupling coefficient obtained from the integration. Computations are carried out for ship with seven wide center tanks and comparisons between the liquid cargo loading case and the rigid cargo loading case are shown.

A matrix partitioning method is proposed for the 2-D motion analysis of floating bodies. For the numerical solution, the boundary of a floating body is approximated with a series of line segments and the governing integral equation is transformed into a system of linear equations. A new solution procedure of resulting linear equation with complex coefficients is formulated and programmed using a matrix partitioning scheme and the Choleski decomposition. From the case study, it is found that the proposed method is efficient in the motion analysis of floating bodies, especially in the calculation of hydrodynamic coefficients. Also, it requires smaller memory size and less computing time compared with conventional methods.

토양수분, 질소시비량 및 도복의 발생 유무가 소맥엽신의 기공개도에 미치는 영향을 알고져 소맥 조광 품종을 공시하여 침윤법으로 개화기에 기공개도의 일중변화를 조사하였던바 그 결과는 다음과 같다. 1. 기공이 폐공되는 시각은 토양수분 Potential이 낮을수록 빨라졌으며 폐공되는 정도도 컸었다. 2. 기공개도는 하위엽이 상위엽에 비하여 작았고 토양수분 Potential 이 낮을수록 기공개도의 감소정도는 더욱 컸다. 3. 도복된 맥체의 기공개도는 정상 맥체에 비하여 작았는데 그 경향은 토양수분 정도 및 측정시각에 관계없이 동일하였다. 4. 질소 보비구는 소비구에 비하여 기공개도가 큰 일중변화를 하였는데 도복구나 건조구에서도 같은 경향이었다. 5. 도복후 일수가 경과함에 따라 기공개도는 크게 감소하였는데 도복후 6 일에는 무도복구에 비하여 50％이하의 개도를 보였으며 그 감소정도는 하위엽이 더욱 컸으며 일중에서는 오후에 현저하였다.

질소의 추비가 소맥엽신의 기공개도에 어떠한 영향을 미치는가를 검토하기 위하여 소맥 조광 품종을 공시하여 질소추비와 무추비구로 처리하여 침윤법으로 최고분얼기, 절간신장기, 수잉기, 개화기, 등숙중기에 기공개도를 측정하였던바 그 결과는 다음과 같다. 1. 소맥엽신의 기공개도는 생육이 진전됨에 따라 증가하여 개화기경에 최대에 달하였으며 그 이후는 저하하였다. 2. 1 일중 기공개도가 최대로 되는 시각은 각시기 모두 정오경이었으며 오후 6시경에는 상당히 폐공 되었으나 이는 생육단계에 따라 다소 상이하였다. 3. 질소의 추비는 엽신의 기공개도를 증가시켰는데 그 정도는 생육이 왕성한 수잉기와 개화기에 특히 큰 경향이었다. 4. 상위엽은 하위엽에 비하여 모든 생육단계에서 큰 기공개도를 나타내었으며, 질소추비에 의한 기공개도의 차이도 상위엽이 하위엽에 비하여 크게 나타나는 경향이었다. 5. 엽신의 질소함량과 1 일중 기공개도의 최대치간에는 고도의 정상관(r=0.66＊＊) 관계가 있었는데, 상위엽과 하위엽 모두 같은 경향이었다. 6. 각 엽기의 엽위간 기공개도의 차는 완전 전개한 최상위엽이 최대치를 나타내었고 전개중인 미성숙엽이나 엽의 노화가 진전된 하위엽일수록 기공개도는 작았다. 7. 각 엽신의 함수중, 근중 및 근의 활력은 질소의 추비에 의하여 증가되었는데 이는 기공개도를 증대시친 한 요인으로 작용한 것으로 추찰되었다.

소맥엽신에 있어서 기공개도의 측정법 및 기공개도의 일변화를 검토하여 광합성연구 및 수분생리 연구의 기초자료를 얻고자 조사하였든 바 그 결과를 요약하면 다음과 같다. 1. 기공개도의 실측치와 침윤법에 의한 시약순위와는 직선적인 비례관계가 있었다. 2. 침윤법으로 측정한 시약순위 1의 경우 기공개도의 실측 평균치는 0.7± 0.5u 이었으며 순위 6의 경우는 6.3± 0.6이었다. 3. 동일엽신내에서도 엽신의 기부는 선단부보다 기공개도가 현저히 컸다. 4. 지엽과 제1엽 엽신의 기공은 10시경에 제2엽은 12시경에 기공개도가 가장 컸으며, 오후가 되면서 기공개도는 감소하기 시작하여 18시경에는 거의 완전히 폐공하였다. 5. 기공개도의 최대치는 지엽보다 제1엽이 또 세력이 왕성한 분벽의 엽신일수록 큰 경향이었다. 6. 엽신기부의 기공은 선단부에 비하여 모든 엽위와 어는 시각에서도 기공개도가 큰 일변화를 보였다. 7. 이상의 결과로부터 소맥엽신의 기공개도 측정은 침윤법으로 가능하나 품종이나 육종재료들에 대하여 기공개도를 비교할 때는 엽위, 엽신부위 및 분벽간에 차가 있으므로 측정재료 선정에 주의가 필요하리라 본다.

In order to evaluate rolling characteristics of high speed container carrier the author developed yaw-sway-rudder coupled rool equation, which is likely to be 5th order differential equation. The free rolling time history with particular reference to automatic steering, was computed upon the base of the yaw-sway-rudder coupled roll equation. The computed result explained effects of C1 and C2 on rolling behaviors and furthermore the effect of C2 proved to be very effective where C1 and C2 are yaw gin constant and yaw-rate gain constant of auto-pilot respectively. Computation was carried out using Matsumoto's data of hydrodynamic force derivatives of 5 meter long container model.

The advanced researches of the ship's motion in the seaway can predict the heaving, pitching and slamming of ship's motion. The researches as of today are that of displacement type such as a small typical fishing boat and U, UV and V bow ship forms under low speed. In recent day, the study of behaviours of high speed planning boat in the regular waves has been carried out by Bessho [5]. The calculation about behaviours of a high speed vessel in the longitudinal regular waves is calculated by Ordinary Strip Method in this paper. The data of the results were discussed and compared with Bessho's results. The conclusions deduced from this study are as follow, (1) The acceleration of motion calculated by the O.S.M. is similar with Bessho's data for the Fn 0.5 (2) The amplitudes of the behaviours of motions take peak at 1.0<λ/L<1.4.