• Korean Journal of Applied Biomechanics
• /
• v.34 no.1
• /
• pp.34-44
• /
• 2024

Objective: This study aimed to investigate how the movements occurring during the follow-through phase after releasing an arrow among elite compound archers, are associated with the arrow impact points on the target. Method: Nine elite archers performed consecutive compound archery shooting under conditions identical to actual competitions using their own bows and equipment. Motion capture system and force platform were utilized to record the changes in joint positions and center of pressure, respectively. Principal component analysis was employed to identify the patterns in which multidimensional joint positions and COP changes were organized with horizontal and vertical coordinates of arrow impact points. Subsequently, correlation analysis quantified the relationship between individual variables and the coordinates of arrow impacts on the target. Results: We found a common organizational pattern in which the two axes of the impact point coordinates were grouped into the first two principal components. The movements of the upper and lower limbs following release exhibited opposite patterns in the anterior-posterior axis, with significant correlations observed between the arrow impact points of the horizontal axis and the left shoulder, right elbow, left hip, and both knees. Additionally, the lateral movements induced by the reaction force upon arrow release showed significant associations with the vertical coordinates of the impact points. Particularly, the correlations between the movements of the left shoulder and elbow, as well as the bilateral hip and right knee, were consistently observed among all participants. Conclusion: These findings implied that the post-release movements could significantly influence the trajectory and impact points of the arrows in compound archery. We suggest that a consistent and controlled movement during the follow-through phase may be more beneficial for optimizing shooting accuracy and precision rather than minimizing movements.

• Journal of Drive and Control
• /
• v.21 no.2
• /
• pp.36-43
• /
• 2024

The yield is basic and necessary information in precision agriculture that reduces input resources and enhances productivity. Yield information is important because it can be used to set up farming plans and evaluate farming results. Yield monitoring systems are commercialized in the United States and Japan but not in Korea. Therefore, such a system must be developed. This study was conducted to develop a yield monitoring system that improved performance by correcting a previously developed flow sensor using a grain tank-weighing system. An impact-plated type flow sensor was installed in a grain tank where grains are placed, and grain tank-weighing sensors were installed under the grain tank to estimate the weight of the grain inside the tank. The grain flow rate and grain weight prediction models showed high correlations, with coefficient of determinations (R2) of 0.9979 and 0.9991, respectively. A main controller of the yield monitoring system that calculated the real-time yield using a sensor output value was also developed and installed in a combine harvester. Field tests of the combine harvester yield monitoring system were conducted in a rice paddy field. The developed yield monitoring system showed high accuracy with an error of 0.13%. Therefore, the newly developed yield monitoring system can be used to predict grain weight with high accuracy.

• The Journal of Korean Society for Radiation Therapy
• /
• v.30 no.1_2
• /
• pp.117-128
• /
• 2018

Purpose : To evaluate the usability of plan transfer between TOMO HD and Radixact, we compared the differences of dose in transferred plans by evaluating the dose of normal organ and target. TOMO HDA and Radixact. The completed plans were transferred each other and we compared the differences of dose by evaluating the DVH of each plans. Materials and Methods : We planned 4 different plans assuming the treatment of 2 cases in Head and Neck Cancer and 2 cases Prostate cancer. Each plan was designed so that 95 % of the prescription dose was irradiated over 99 % of the target volume, and the normal organ constraints dose was based on the SMC tolerance dose protocol. Each plan was transferred to each equipment and DVH(dose volume histogram) analysis of the transferred plans was compared and evaluated. Results : The Mean dose of CTV and GTV was increased and decreased in the transferred plans, but there was no significant differences. The target coverage of CTV and GTV was decreased in all cases of transferred plans from TOMO HAD to Radixact, and the change of CI and HI in CTV was within 0.1. Normal organ dose was increased in most cases when transferring from HAD to Radixact in both treatment plans. Conclusion : According to the results of this experiment, the target coverage was above the standard and the normal organ dose was almost same or decreased when transferring the plans from Radixact to HDA equipment. However the target coverage was reduced when transferring the plans from HDA to Radixact and there was an increase in dose in normal organs that could cause sever side effects such as Optic Chiasm ($D_{max}$1.38 Gy), Bladder ($D_{max}$3.07 Gy), Penile Bulb ($D_{max}$1.14 Gy). Therefore, it is necessary to pay attention to the dose change when transferring the plan and one-time transfer due to equipment inspection will be useful for efficient radiation therapy, but if the transferred treatment plans continue for several consecutive days, the treatment plan should be resumed.

• Journal of Bio-Environment Control
• /
• v.22 no.4
• /
• pp.303-308
• /
• 2013

A remote controlled sprayer has designed, manufactured and experimented to spray well on pear trees with pesticides. This study was executed to automate pest management of pear trees. Types of spray nozzle, which was used on the system, were analyzed experimentally to find an optimal spray equipment configuration with several nozzles. Attributions of ultrasonic sensors were analyzed to adjust spraying distance of an unmanned sprayer system. This paper investigated shapes of pear trees and cultivating environment of pear orchard. In order to select optimal spray environment, liquid distribution was measured while angle of nozzle was changed. Additionally, liquid distribution by distance and sprayed liquid capacity by side distance were measured. According to information of shapes of pear trees and cultivating environment of pear orchard, sprayer frames of an unmanned sprayer system were manufactured and sprayer frames were suitable for interval of pear trees. The sprayer system could adjust width of sprayer frames to 2.5 m and height of sprayer frames to 1.7 m. Optimal angle of nozzle, and optimal distance between objects and nozzle were $15^{\circ}$ and 0.8 m. When side distance was placed from 1.2 m to 1.8 m, sprayed capacity reached to the highest amount.

• Journal of radiological science and technology
• /
• v.37 no.4
• /
• pp.273-278
• /
• 2014

Bone density measurement use of diagnosis of osteoporosis and it is an important indicator for treatment as well as prevention. But errors in degree of precision of BMD can be occurred by status of patient, bone densitometer and radiological technologist. Therefore the author evaluated that how BMD changes according to the condition of the patient. As Lumbar region, which could lead to substantial effects on bone density by diverse factors such as the water, food, intentional bowels. We recognized a change of bone mineral density in accordance with the height of the water tank and in the presence or absence of the gas using the Aluminum Spine Phantom. We also figured out the influence of bone mineral density by increasing the water and food into a target on the volunteers. Measured bone mineral density through Aluminum Spine Phantom had statistically significant difference accordance with increasing the height of water tank(p=0.026). There was no significant difference in BMD according to the existence of the bowl gas(p=0.587). There was no significant difference in a study of six people targeted volunteers in the presence or absence of the food(p=0.812). And also there was no significant difference according to the existence of water(p=0.618). If it is not difficult to recognize the surround of bone in measuring BMD of lumbar bone, it is not the factor which has the great effect on bone mineral density whether the test is after endoscopic examination of large intestine and patient's fast or not.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.4 no.5
• /
• pp.442-448
• /
• 1999

We introduce the systematization design method using similarity theory which is profitable in the c compatability and standardization of the developed products and the reduction of construction time and price to d develop and design a machine equipment. Systematization design method is to select the standard model for d designing and developing from the large machinery to the super precision one and then to induce the c characteristic of machines step by step in advance in case of miniaturizing and making largelongleftarrowscale. With this m method, we extract the peculiar characteristics through the close analysis on the physical and ttx:hnical part a and predict the characteristic experiment for the magnitude we desire by an머ogical mathematical analysis. At l last, we will get the design sample the users demand with the verification of the data on optimum design p previously. In this paper, we could predict the characteristic of the product the users rC'Quire in advance with the d design method applying similarity theor${\gamma}$ and suggested the design method which could meet the various r requirements the users want. Also, it is shown that the standardization design by the similarity theory is a available as comparing the characteristic values expc'Cted through the experiment of the actual actuator with t the theoretical character data of similarity theoη after selecting the linear actuator as a model.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.39 no.3
• /
• pp.218-229
• /
• 2003

A new biotelemetry method that the installation and the treatment of equipment is convenient and the instantaneously detailed location of the fish attached the pinger is able to track comparatively easily was developed. The receiving system in this biotelemetry method was advanced for track the detailed behavior of the fish by the miniature tracking pinger, because it was a burden to fish to add the pinger with the water temperature and the pressure sensor. By combining of the super short base line (SSBL) method to detect the direction of pinger and the pinger synchronizing method to measure the range from receiving transducer to pinger, the three dimensional locations of fish to the receiving transducer is gotten instantaneously. The receiving system is devised to realize the high precision or wide detection range by application of the basic design method for receiving system of biotelemetry developed by the present authors and the hydrophone array configuration. The measurement distance error in the pinger synchronizing method is minimized through the correction of which the deviation of transmission pluse period of pinger is caused by changing water temperature. A prototype system which is able to track the instantaneously detailed location of the fish by the SSBL and pinger synchronizing biotelemetry (SPB) method was produced.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.5
• /
• pp.1-6
• /
• 2020

UAV (Unmanned Aerial Vehicles) are used widely for military purposes because they are more economical than general manned aircraft and satellites, and have easy access to the object. Recently, owing to the development of IT technology, UAV equipped with various sensors have been released, and their use is increasing in a wide range of fields, such as surveying, agriculture, meteorological observation, communication, broadcasting, and sports. An increasing number of studies and attempts have made use of it. On the other hand, existing research was related mostly to photogrammetry, but there has been a lack of analytical research on LiDAR (Light Detection And Ranging). Therefore, this study examined the characteristics of a UAV LiDAR sensor for the application of a geospatial information field. In this study, the performance of commercialized LiDAR sensors, such as the acquisition speed and the number of echoes, was investigated, and data acquisition and analysis were conducted by selecting Surveyor Ultra and VX15 models with similar accuracy and data acquisition distances. As a result, a DSM of each study site was generated for each sensor, and the characteristics of data density, precision, and acquisition of ground data from vegetation areas were presented through comparison. In addition, the UAV LiDAR sensor showed an accuracy of 0.03m ~ 0.05m. Hence, it is necessary to select equipment considering the characteristics of data for effective use. In the future, the use of UAV LiDAR may be suggested if additional data can be obtained and analyzed for various areas, such as urban areas and forest areas.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.40 no.1
• /
• pp.78-85
• /
• 2004

The new biotelemetry method and system that the installation and the treatment of equipment is convenient and the instantaneously detailed position of the fish attached a pinger is able to track comparatively easily had been developed, an practicality of it were verified in the water tank and the small sea port through the tracking of fish. The biotelemetry method had been gotten the three dimensional locations of fish to the receiving transducer by combining of the super short base line (SSBL) method to detect the direction of pinger and the pinger synchronizing method to measure the range from receiving transducer to pinger. The receiving system had been designed to realize the high precision or wide detection range by application of the basic design method for receiving system of biotelemetry and the hydrophone array configuration. From tracking test of carp in the water tank, the migration course and the velocity of carp was investigated and the observed migration course was compared with measurement. The measured migration course of carp coincided with the observation in the main and the position of carp was able to track three dimensionally. The velocity of carp measured by the moving average method was 11.2cm/s. From tracking test of yellowtail in the small sea port, the migration course and the velocity of yellowtail was investigated at natural condition. The position of yellowtail was able to track three dimensionally and the velocity of it measured by moving average method was 43.9cm/s.

• Journal of East Asia Management
• /
• v.1 no.1
• /
• pp.65-87
• /
• 2020

In recent years, with the rapid development of network live streaming, with the popularization of mobile Internet and mobile terminal equipment, the live streaming industry has ushered in great development. A sudden outbreak of the COVID-19 makes the PC end live streaming which has been developed for many years enter a new era, giving birth to the rapid development of mobile end live streaming. Not only because of the expansion of the live streaming industry market, the rise of the trend of the national live streaming, but also because the mobile live streaming is more and more valued by the brand, becoming an important tool for brand communication and product promotion. It is because of its unique communication characteristics that some scholars believe that the era of precision marketing has been opened by live network. Mobile live from the initial fans to reward and promote the brand, to now in the form of live marketing, consumers can "buy while watching". The time period from the understanding of the goods to the final completion of the purchase behavior has been greatly shortened. It is conducive to improving sales volume and brand awareness. Marketing communication through mobile live platform has become a popular way of brand marketing. This paper mainly studies the current situation, methods, problems and development strategies of brand marketing activities with the help of live streaming platform under the background of mobile internet. Taking Tmall live streaming platform as an example, this paper analyzes several ways of brand marketing with the help of live streaming and some universal characteristics of live streaming marketing by using the relevant theories of marketing. In view of the problems existing in live streaming brand marketing, it puts forward relevant Improvement measures. First of all, the paper puts forward the innovation in content and form. Second, the paper suggests that we should make full use of new technologies such as AR and VR to effectively combine with mobile live broadcasting. Third, the paper explores the integration of multiple channels to create intelligent marketing, and further optimize the live interface of mobile terminals. Finally, the paper emphasizes that the government departments and the platform itself should jointly supervise the mobile network live streaming platform and establish a good live broadcasting environment for mobile terminals. With the help of mobile live streaming, the marketing mode has an important impact on the promotion of brand marketing. How to make better use of this business mode and accurately use mobile live broadcast to promote brand marketing, so that enterprises can create greater profits, is also of profound research significance.