• Korean Journal of Applied Biomechanics
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• v.20 no.2
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• pp.239-243
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• 2010

The putting stroke accounts for 40~50% of total stroke for a golf rounding and most golfers have difficulties on the puting. Studies for the putting stroke have been conducted by analyzing various factors such as kinematics, kinetics, psychologic and physiologic parameters. A lot of devices were developed to support the studies. However there was no appropriate method to measure the position of the ball quantitatively. In this study, we developed a new measurement system to measure and evaluate the putting result. The developed system uses a USB camera to take the 2-dimensional image of the surface including the hole cup at the center of the image and the ball. The position of the ball is extracted as a set of distance and angle in polar coordinate system. We evaluated the new system with an indoor set-up for putting experiments and the system provided accurate measurement results. The proposed system can be combined with the other measurement systems such as 3D motion capture system and force plate without any restriction.

• Korean Journal of Applied Biomechanics
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• v.16 no.1
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• pp.43-53
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• 2006

Among several movements that occurred upon a slope, golf swing is the most typical one because environmental conditions dynamically vary with many kinds of slopes. Some studies on the golf swing were performed about a weight transfer on flatland, however, there couldn't be seen any study about the weight transfer on slope elsewhere. Therefore, the purpose of this study was to provide quantified data to objectively test the coaching words and keys about the weight transfer at sidehill slope during goal impact EspeciaIly sidehill Slopes with ball above the feet. Four highschool golfer, who have average handy 5, were recruited for this study. Plantar pressure distribution and cinematographic data were collected during golf swing in the conditions of flatland, $5^{\circ}$, $10^{\circ}$ and $15^{\circ}$sidehill slope simultaneously. The two data were used to synchronize the two data later. The plantar regions under the foot were divided into 8 regions according to the directly applied pressure pattern of the subject to insole sensor. The 8 foot regions were hullux, medial forefoot, central forefoot, lateral forefoot, medial midfoot, lateral midfoot, medial heel, and lateral heel. And the plantar pressure data was also divided into four movement address, phases-backswing. downswing, and follow-through phases according to the percentage shown to the visual information of film data. Based on the investigations on public golf books and experiences of golfers, it was hypothesized by the authors in the early of this study that the steeper slopes are, the more weight loads on left foot that positions at the higher place. When observing the results of plantar pressure and vertical force curves according to the sidehill slope conditions, the hypothesis could be accepted.

• Korean Journal of Applied Biomechanics
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• v.15 no.3
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• pp.79-94
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• 2005

Because the golf swing is very complex movement, it is varied in different gender, skill level, and club. This study measured kinematic variables in golf swing regarding gender, skill level, and club types using FasTrak electromagnetic tracking system. Golf swing kinematics including time variables, linear and angular displacement variables, angular velocity variables were analyzed and compared through three-way ANOVA The results were as follows: 1. In time variables, Female and driver showed longer backswing time than male and iron. Downswing time was longer in female and nonexperts than male and experts. Backswing time over downswing time was longer in experts than nonexperts. Uncocking time was longer in male and experts than female and nonexperts. The differences were statistically significant (p<.05). 2. In displacement variables, Female and nonexperts showed greater backswing head lift than male and experts. Impact head lift was greater in female, nonexperts, and iron than male, experts, and driver. The differences were statistically significant (p<.05). Experts and driver showed greater top hip rotation angle than nonexperts and iron. Top shoulder rotation angle was greater in male, experts and driver than female, nonexperts, and iron. X-factor was greater in male, experts, and driver than female, nonexperts, and iron. Male and experts showed greater backswing hip sway than female and nonexperts. Impact hip sway was greater in male and iron than female and driver. The differences were statistically significant (p<.05). 3. In velocity variables, Experts displayed higher impact hip rotation velocity than nonexperts. Impact shoulder rotation velocity was greater in male and iron than female and driver (p<.05).

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.109-112
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• 2001

In this paper, the development of the prototype electric vehicle for golf car is described. A brushless dc (BLDC) motor is applied as a prime mover. The BLDC motor is coupled directly to the reduction and differential gear system. The output power of the motor is decided to 2.2Kw at 3000 rpm, which is a general value of the golf car on the market today. The motor is driven by the microprocessor-based 3-phase PWM inverter system. We introduce the performance and functions of the BLDC motor and it's control system.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.4
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• pp.25-34
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• 2010

This study was conducted to develop evaluation indicators to improve athletic performance and operational management of golf courses and the results of the research are as follows. Through theoretical research and a preliminary professional survey, 15 on-going evaluations of golf course composition and operational management and 55 sub-evaluation indices were rejected while 10 on-going evaluations and 52 sub-evaluation indicators were reconfigured as final for environmental-friendliness, level of member services, level of human service of game personnel, difficulties of course, management level of the course, fairness of operational management, accessibility and location characteristic, traditions and ambiance of the golf club, quality of course, and course layout. When analyzing the important decision factors in golf course user preference evaluation indicators, the following contributed in the order of higher to lower contributions: the management level of the course, excellence of the course, level of human services for personnel, course layout and environmental-friendliness. When identifying the path coefficient of golf course evaluation indicators, the curvature of a hole and the length of the course had a causal effect on the 'course layout' section. Tournament facilities and various shot values had a causal relationship with 'excellence of the course', in the order of higher to lower, and convenience of waiting and fair allocation of reservations for 'fairness of operational management'. The history of the golf course and its environmental characteristics, history and culture of the region have relatively higher causal effects on 'traditions of the golf club' and geographical conditions on 'accessibility and location characteristics', pesticide and fertilizer usage and water pollution on 'environmental-friendliness', and member benefit and kindness of employees on 'level of member services'. The kindness and expertise of the game personnel had a relatively higher causal effect on the 'level of human services of game personnel', the location of tenning area, and location of OB and hazards on 'difficulties of course', and rough conditions and obstacles management on 'management level of the course'. There is a need to complete a systematic evaluation index system for golf course user preferences through future studies for a more detailed assessment, as well as a process to verify these evaluation indicators by application to domestic and international golf courses.

• Korean Journal of Agricultural Science
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• v.38 no.2
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• pp.243-248
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• 2011

This investigation was conducted to develop an integrated disease management system against large patch disease occurred in a golf course. Large patch, brown patch, and Rhizoctonia blight sometimes are used interchangeably by turfgrass managers and researchers, Large patch disease of zoysiagrass is caused by a soilborne fungus called Rhizoctonia solani. Although this fungus is very similar to the one that causes brown patch disease of cool-season turfgrasses in mid-summer. Large patch development is favored by high thatch and soil moisture. Avoid overwatering the turfgrass, especially in the fall or early spring. Poorly-drained areas are very susceptible to injury from large patch and should be reconstructed (draining tiles, etc) to avoid soil saturation. However, control of yellow patch with fungicides is normally not recommended because the disease has only cosmetic effects and symptoms are usually very short-lived. Therefore, we reviewed the symptom of large patch to look for control method by soil management method.

• Journal of Environmental Impact Assessment
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• v.18 no.5
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• pp.313-319
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• 2009

A complex maritime resort combined marina and with course of Korea is required to improve international tourism competitiveness by taking advantage of her environmental favorable circumstances. The development of tourism, however, is focused on land-oriented that incurred lower tourism efficiency and international tourism competitiveness. In addition, the regulation of "Preliminary environmental assessment for golf courses" by the Ministry of Environment is emphasized on land geography and geology that can cause damage of tourist attractions in an island region. In particular, the development of 6th or 7th ridges in mountainous island region within 2km from the sea, that holds scenic and academic value, can go against environment-friendly by geographical and geological damage. According to the regulation for consultation for golf courses and forestry is to preserve regional ecosystem over 6th ridge, but it cannot be applicable to island region because that can form excessive slopes where marine ecosystem is required to be maintained. It, therefore, can be desirable that the development of over 6th ridge in an island region. It is suggested that continuous comparative studies of geographical and geological characteristics between land and island region will be carried on to establish feasible and reasonable development model so that balanced development of land and island, and versatile international environment-friendly maritime resort can be achieved and developed.

• Journal of the Korea Society of Computer and Information
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• v.11 no.5 s.43
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• pp.53-58
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• 2006

In this paper, I propose an image based feature extraction method for an automatic golf swing analysis. While most swing analysis systems require an expert like teaching professional, the proposed method enables an automatic swing analysis without a professional. The extracted features for swing analysis include not only key frames such as addressing, backward swing, top, forward swing, impact, and follow-through swing but also important positions of golfer's body parts such as hands, shoulders, club head, feet, knee. To see the effectiveness of the proposed method. I tested it for several swing pictures. Experimental results show that the proposed method is effective for extracting important swing features. Further research is under going to develop an automatic swing analysis system using the proposed features.

• Asian Journal of Turfgrass Science
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• v.7 no.2_3
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• pp.55-60
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• 1993

Soil profile was well developed into four horizons, $A_1$, $A_3$, $B_2$and C at 100cm-depth in most four golf courses in Kyonggi province. Distribution of root system of Korean lawngrass was abundant in dark yellowish or yellowish brown $A_1$ horizon with low hardness(8~14mm yamanaka scale), moderately in yellowish brown $A_3$ horizon with moderate hardness(16~23mm) rarely in $B_3$horizon(15~60cm depth) and no in C horizon. Optimum soil hardness for good root growth of Korean lawngrass appeared to be less than 16mm mineral nutrient contents. Such as Ca++, Mg++, K+, Mn++ and Fe showed relatively higher concentration in lower horizon indicating the leaching of minerals. The increasing tendency of soil pH with depth seemed to the result of mineral leaching. There was significant positive correlation between Ca+Mg and pH, manganese content appeared to be too high(261~789ppm) in $A_1$ horizon. The contents of organic matter and phosphorus were bight in $A_1$ horizon and greatly varied among golf courses.

• The Journal of the Acoustical Society of Korea
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• v.28 no.7
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• pp.674-679
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• 2009

This paper proposes a method of player event retrieval using combination of two functions: detection of player name in speech information and detection of sound event from audio information in golf videos. The system consists of indexing module and retrieval module. At the indexing time audio segmentation and noise reduction are applied to audio stream demultiplexed from the golf videos. The noise-reduced speech is then fed into speech recognizer, which outputs spoken descriptors. The player name and sound event are indexed by the spoken descriptors. At search time, text query is converted into phoneme sequences. The lists of each query term are retrieved through a description matcher to identify full and partial phrase hits. For the retrieval of the player name, this paper compares the results of word-based, phoneme-based, and hybrid approach.